This sinkhole in Fackler sucks many a keen caver into its depths. It drops for 162 feet (49m), with a 40-foot (12m) diameter, and the only way to the bottom is straight down. Those wishing to explore the mysterious cavern must acquire a special permit, before making the vertical ascent into the abyss using the proper caving equipment. But even just peering into the cave's moss-covered depths is enough to give anyone goosebumps.

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Beating a 414-mile (666km), mountain-flanked path from the tiny town of Livengood to Deadhorse in northern Alaska, this far-flung road isn’t for the faint-hearted. It's the sheer remoteness that spooks people – it’s possible to travel for hours and hours without glimpsing another human being – or indeed a petrol station, a toilet, or any kind of shop. The sub-zero temperatures and icy conditions only add to the fear factor.

The best advice for tackling this hair-raising mountain-bike trail? Don't look down. Or, just… don't. One of the most perilous routes in the world, it's the domain of the most daring and masterful bikers. The mind-bendingly narrow path is etched into a cliff face in Sedona, with a near-vertical drop on one side. The slightest wrong move would send helpless bikers careering over the edge.

The highest point in the Natural State, Mount Magazine sits at 2,753 feet (839m), offering panoramic views across its namesake park. For some, the vistas at this vertigo-inducing height will be enough – but the fear factor can be raised even more. Daredevils can take a shuddering ATV ride, rock climb up the mountain's face, or launch themselves from its summit on a hang glider.

So-named because it’s located in the heart of the Angeles National Forest, some five miles (8km) from the nearest road, the Bridge to Nowhere is certainly off the beaten track. But visitors looking to turn up the thrill factor a few notches can bungee jump off the 120-foot (37m) tall bridge and plummet into the valley below. Bungee America runs California’s only certified bungee jumping site from here, so for adrenaline seekers in the state, this is a must.

This legendary road, which spools out from Glenwood Springs to Granite, has no shortage of dicey sections along the way. The hairiest of all is Independence Pass, which is only open between May and November each year, given its perilous conditions during the wintertime. But the razor-sharp bends, single-lane tracts and frequent rock fall mean the highway is a risk at any time of year. Donning a seatbelt is non-negotiable.

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Foxwoods Resort and Casino offers guests a dose of adrenaline away from the blackjack table. The mile-long HighFlyer zip line lets riders glide over Connecticut's Mashantucket woodland at a height of 350 feet (107m). Those brave enough to try it will be propelled from the resort's own Fox Tower, and finish up at the Mashantucket Pequot Museum and Research Center. The reward? Jaw-dropping treetop views along the way. 

As far as teeth-chattering roller coasters are concerned, Delaware might not be the first place that comes to mind. But Rehoboth Beach's Funland park has something to take on Florida's monstrous offerings. As the name suggests, this ride tips daring passengers upside down as its giant arm swings full circle, from ground level to 40 feet (12m) in one fell swoop. Needless to say, this isn’t one to tackle straight after lunch...

Orlando is the thrill-ride capital of America, so it's no wonder it has some of the most adrenaline-pumping attractions. For a time, the StarFlyer ride in the ICON Orlando 360 complex was the tallest swing ride in the world, and while it was recently overtaken by Dubai’s Bollywood Skyflyer, it’s still impressively high. Rising to 450 feet (137m), the attraction swings riders, arms raised, legs dangling, round and round, above the city.

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Not one for the uninitiated, this extreme white-water run is set along the roaring Chattooga River, on the South Carolina border. The frothing rapid is classified as a Class Five (advanced), and drops 14 feet (4.3m) over its course. Those preferring not to make a splash can watch rafters battle the waters from the rocky Bull Sluice hiking trail. 

Spitting Caves is one of the most popular cliff-jumping spots in Hawaii. Divers launch themselves from the undulating rocks –  as high as 70 feet (21m) in places – and into the frothing waves below. They then have to contend with merciless underwater currents which suck them towards the cliffs. Even for those who don’t dare to dive, the rocks can be perilously slippery, and just looking at the swirling waves below can be terror-inducing.

Another destination for adrenaline junkies is the Perrine Bridge in Idaho's Twin Falls. This is a favoured spot for BASE jumpers, who throw themselves from the 486-foot (148m) bridge, usually wearing a wing suit, before parachuting their way down towards Snake River Canyon. Though it's generally the domain of experts, companies such as Tandem Base allow visitors to try it for themselves – strapped to a pro, of course.

Prone to vertigo? Look away now. Even just glancing at this attraction is a dizzying experience. The glass-floored “Ledge”, which juts out from the Willis Tower's observation deck at a head-spinning height of 1,353 feet (412m), offers brave visitors the chance to look out (and down) at epic views of the Windy City. From this height, it looks more like a toy town.

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For those who like their sky-high views with a side of sheer terror, Skydive Indianapolis is just the ticket. Located at Frankfort Municipal Airport, the centre has one of the highest safety ratings in the country, so skydivers can relax (a bit) about being flown some 13,000 feet (3,962m) into the air to free-fall at a whopping 120 miles per hour (193km/h).

This bright green juggernaut has a fitting name. The Monster, in Altoona's Adventureland theme park, includes a more-than-vertical drop at the beginning of its twisting track, which passengers shoot along at 65 miles per hour (105km/h). The rest of the route is a rattling ride with plenty of diving loops – that means passengers are shot upwards, before plummeting back towards the earth in a stomach-flipping spiral. 

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Got the need for speed? While watching race cars zoom around a track may be thrilling enough for some, this Kansas City speedway allows amateurs to get behind the wheel themselves. There are two options: a “ride-along” experience, where visitors can sit up front with a professional NASCAR racing driver, or brave souls can even take the wheel themselves (after training with a pro, of course).

There are subterranean thrills aplenty at this unique zip-line attraction in Louisville. There are six lines in total and visitors are fed nuggets of geology wisdom by enthusiastic guides as they speed across the limestone cavern. The cave includes more than 17 miles (27km) of passageways, and a zip line course exploring it can take up to two and a half hours. Those without a head for heights could try a tram ride, or a whizz around the underground bike park.

This wetland preserve in Jean Lafitte National Historical Park is as hair-raising as it is beautiful. It's a leafy, swamp area criss-crossed with boardwalks, and a large population of alligators call its waters home. Those with an appetite for adventure can check out the scaly creatures while following the trails, or from a canoe ride – but keeping at least 30 feet (9m) away is recommended.

The name really says it all. The Knife Edge Trail in Baxter State Park, reaching across the peak of Mount Katahdin, is heart-pumpingly narrow in places – it also has sheer drops of 2,000 feet (610m) on each side. The terrain is rocky, and the wind unrelenting, so this really is the preserve of the expert hiker. Those who do tackle it are richly rewarded, though, with mesmerising views across the park.

Not all bridges are created equal, and this gargantuan feat is one of the longest in the USA. It stretches 4.3 miles (6.9km) over its namesake, Chesapeake Bay, and nervous drivers lament the lack of hard shoulder and battering winds as they travel across it. So many are scared of crossing the bridge's expanse that there are now dedicated taxi services to ferry people across – companies such as the Kent Island Express drive jittery passengers over it in their own car for a fee. 

Monroe Bridge, also known as the Dryway, is a challenging five-mile (8km) stretch of white water along the Deerfield River in northwest Massachusetts. This class II–IV run gets off to a fairly easy start, but the pace soon picks up. Rafters have to grapple with stretches nicknamed "Dragon's Tooth" and the "Terminator", where strong paddling and expert maneuvering are essential to clearing the strong currents and steep drops.

A mammoth suspension structure dating back to the 1950s, Mackinac Bridge (known to locals as “Mighty Mac”) has a total length of 26,372 feet (8,038m). It extends over the Straits of Mackinac, connecting Mackinaw City on Michigan's Lower Peninsula, to the city of St Ignace, in the Upper Peninsula. If the bridge's sheer size and length didn't make it a daunting enough drive, then consider the fact that, despite its mass, it tends to move with the wind. Not exactly a “breezy” drive...

One of the most dizzying thrill rides in the Midwest, Xtreme Swing catapults thrill-seekers over the Valleyfair theme park at a height of 125 feet (38m). Soaring through the air at 60 miles per hour (97km/h), passengers will have just enough time to drink in the surroundings – from the Minnesota River to the other stomach-churning rides – before being hurled back the way they came.

Tucked in the heart of the thick woodland of Perkinston, there are three soaring ropes courses to choose from at Elevate Red Creek. The most intimidating of all is the "Osprey" challenge: at the highest point, obstacles are suspended at 50 feet (15m) in the air, with zip lines, rope ladders and dangling stairs to contend with. There are cabins to rent here for those wishing to extend the thrills. 

In 2018, Branson’s Silver Dollar City launched its record-breaking Time Traveler ride, touted as the fastest, steepest and tallest spinning coaster in the world. The coaster has all the dips, flips and inversions of a regular roller coaster, with the added thrill that the car itself rotates as it rattles across the 3,020-foot (920m) track. 

For snowy adventures, Montana's Big Sky ski resort is a must. While Colorado usually comes top when it comes to head-spinning ski runs, Big Sky's Lone Peak will satisfy the most gallant of snow pounders. There are more than 3,500 acres of terrain for advanced or expert skiers here – the Lone Peak Tram takes skiers 11,166 feet (3,403m) up the bluff, ready for an adrenaline-fuelled path back down it. Plus, there are stunning vistas across Yellowstone National Park.

This 6,000-foot (1,829m) cavern, with its dark corners, low ceilings and tight spaces, is bound to send chills down anyone’s spine. It's one of only two mines of its kind in the entire United States, which adds to its mystery. Closed in the 1970s, since it was deemed unsafe, guided tours began again in 1997, following renovation efforts. Tours go into the cave's low-lit depths, telling visitors of its history as a chalk mine and an "underground playground" for locals.

While many might not want to tear themselves away from the slot machines, there are plenty of other adrenaline-pumping experiences in Sin City. The aptly-named Insanity ride catapults passengers through the skies at some 900 feet (274m) high, and at such speeds that downtown Las Vegas becomes a neon blur below. “Don’t look down” is futile advice here. 

This is not the tallest peak in the US (those records sit with mighty bluffs in Alaska), but it’s not to be underestimated. An ominous, snow-covered peak, Mount Washington sits in the White Mountains' Presidential Range, at a colossal height of 6,288 feet (1,917m). Its unpredictable weather, considered some of the most extreme on Earth, is what makes it so fearful – galing winds and heavy snow, in winter especially, means a hike here will feel like a foray into the Arctic. Only experienced hikers should attempt it. 

The world's tallest and fastest drop ride lives at Six Flags Great Adventure in New Jersey. Three benches transport rows of awestruck riders up 415 feet (126m) to the top of the structure. Then there's a momentary, unnerving pause, before they fall, full throttle, back towards the ground, at speeds of up to 90 miles per hour (145km/h). Needless to say, passengers' stomachs are left somewhere around their ears.

Many of the mightiest ski slopes can be found in California or Colorado, but some of the runs at this New Mexico resort are not for the faint-hearted. The trails down Kachina Peak are the gnarliest of them all – the mountain’s summit stands at more than 12,000 feet (3,658m) above sea level, and just gazing up at it is enough to make anyone dizzy. Expert and advanced skiers should take the ski lift to the top and pound the black diamond-rated runs.

Zipping over the forest at New York's Hunter Mountain is a sure-fire way to get the heart pumping. New York Zipline Canopy Tours offers an array of fun for adventure-seekers. There are 3,200 feet (975m) of zip lines, and it's supposedly the longest, fastest and highest course in North America.

Drivers should keep a firm focus ahead when tackling this long and winding road. The highway, known as Tail of the Dragon for its many curls and bends, has more than 300 turns in total, cloaked by woodland on either side. A portion of the US-129 Highway, spooling into Tennessee, it attracts thrill-seeking motor-car drivers and bikers. 

One of the most challenging biking routes in the States, the 144-mile (232km) long Maah Daah Hey trail slices through bluffs and badlands, with steep terrain and jaw-dropping views all around. It has its southern trailhead at the US Forest Service Burning Coal Vein Campground, weaving its way north to the CCC Campground in McKenzie County. The most precarious point of all is Devil's Pass: this narrow pathway has a 150-foot (46m) drop each side and plenty of hairpin bends.

For more than a decade, zip lines have been laced through the tree-tops of Ohio's picturesque Hocking Hills area, withs it clifftops and caves and green canopy. Hocking Hills Canopy Tours has the most extensive offering. The Superzip is a knee-knocking option, allowing visitors to fly through the forest at 85 feet (26m). Another daring choice is the X Tour, which not only courses through the treetops, but into a cave and across the river too.

At a lofty 80 feet (24m), this obstacle course by Riversport OKC is purportedly the tallest adventure course of its kind in the world. Adventurous types can work their way through increasingly challenging hurdles, from swaying bridges to wobbling beams, while the course terminates with the intimidating “Rumble Drop” – an 80-foot (24m) tower and free-fall experience. Or, for those wanting a (slightly) less terrifying descent, there’s a 700-foot (213m) zipline to soar down instead. 

The 650-acre Smith Rock State Park is a playground for adrenaline junkies. It sits at an elevation of around 3,000 feet (914m), with all manner of intimidating peaks and precipices. It's a popular place for the death-defying pursuit of slacklining: a wire is suspended between two cliff crests, allowing daredevils to cross it like a tightrope. For those after thrills without quite the same level of fear factor, there are plenty of places for more traditional climbs.

If ever there was a place to tackle a fear of heights, this is it. This teetering skywalk is located in northwest Pennsylvania’s Allegheny National Forest, and was built from the Kinzua Viaduct, a former railroad bridge (once the tallest of its kind in the world) that was destroyed by a tornado in 2003. Instead of returning the bridge to its original function, the state chose to turn it into a dramatic observation deck. It looms some 225 feet (69m) above the perilous-looking Kinzua Gorge.

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You wouldn't normally expect to get your thrills from a zoo, but hear us out. The Roger Williams Park Zoo, already a family favourite, added a new attraction to please adventure-seekers in 2017. The Soaring Eagle Zip Ride allows visitors to get a birds-eye view of the site, and the city of Providence beyond, as it glides 115 feet (35m) in the air. The cars allow for two people to sit alongside each other, so it's a treat for kids too.

Table Rock is the namesake of this breathtaking park. But Pinnacle Mountain – the tallest peak entirely within state borders – is the one that attracts the daredevils. And it’s easy to see why. Standing at an awesome 3,415 feet (1041m) tall, it’s laced with plenty of challenging hiking trails: the three-mile (5km) Pinnacle Mountain trail is one of the best ways to reach the summit. 

Despite the fear-inducing name, Falling Rock draws climbers from all over the state. The limestone bluffs here allow for vertical climbs of up to 40 feet (12m), and can be found some six miles (10km) outside of Rapid City. For those wishing to tackle a climb, it’s advisable to do it outside of the summer months, when the heat can be overpowering. 

The Great Smoky Mountains National Park has no shortage of staggering scenery – but this, the highest point at 6,643 feet (2,024m), takes some beating. The Clingmans Dome Observation Tower itself is a 45-foot (14m) structure, reached by ascending a winding pathway. Those who can swallow their fears and walk to the edge of the tower will be rewarded with endless views out across the spruce-fir-forest-covered mountains.

One of the tallest observation towers in America, this 750-foot (229m) viewing platform can be found in the Tower of the Americas building, alongside its bar, restaurant and 4D ride. A glass-fronted elevator allows visitors to take in vistas of downtown before they even reach the top. In the viewing area, historical displays help make sense of the pocket-sized buildings below.

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There are plenty of ways to get the adrenaline pumping at this Olympic Park near Salt Lake City. The quickest, though, comes in the form of the Drop Tower: a 377-foot (115m) zip line that culminates in a 65-foot (20m) tower, from which daring visitors must free-fall. Other attractions include the 25-foot (7.6m) high ropes course, extreme tubing – which is essentially careening down a hill at up to 50 miles per hour (80km/h) – and a chance to try out bob-sledding.

"Ski it if you can" is the strapline of this ski resort in Vermont's Green Mountains. And, touted as one of the most difficult ski runs in the States, the Paradise Trail is one for the pros. The course has a single black diamond rating, steep drops of eight feet (2.4m) along its course, and plenty of trees to dodge along the way. The single-chair ski lift (the last surviving one in the States) adds to the tension, since skiers have no-one to calm their nerves on the way up.

This is the highest mountain in Virginia, reaching 5,729 feet (1,746m) above sea level at its peak. A challenging hiking trail works its way towards the summit, with dense spruce-fir forest hemming the pathways. Visitors should watch out for moving rocks on the route, which beats on for more than 10 miles (16km), with wild flowers and Highland ponies to be spotted along the way.

This sky-high bridge, dating back to 1935, has its home in Washington's most visited state park. It arches 180 feet (55m) above the waters of both Deception Pass and Canoe Pass strait, and is made even more unnerving when fog curls around its expanse. There are two options for taking it all in: gazing up at the bridge from a boat, or taking to its (very narrow) pedestrian pathway to look down at the rushing waters below.

This nerve-jangling white-water run has earned itself the moniker the "Beast of the East". A Class V stretch on the Gauley River, it's made up of 12-foot (3.7m) drops and powerful rapids that will test even the most advanced of rafters. Lost Paddle is one of the most challenging rapids along the way: a lengthy, unrelenting stretch, it includes four stomach-churning drops.

Chimney Rock Park is ripe for the adventure seeker, filled as it is with lofty, castellated mounds. To make the most of its heights, adventure company Vertical Illusions offers climbing, zip-lining and abseiling activities within the park. There are 18 zip lines, letting visitors whizz above cliffs and canyons. Keen climbers should book onto one of their half-day tours to scramble up craggy rock faces and rappel back down them.

One of the most notorious ski runs in the world, let alone the States, Corbet's Couloir at Jackson Hole boasts a near-vertical drop, and is hemmed in by rough rock, only ten feet wide at its opening. Nerves of steel are essential here and it's not uncommon for even the most experienced skier to wipe out immediately and free fall up to 20 feet (6m) depending on conditions. A safer alternative is to watch from the nearby tram stop, which acts as a viewing gallery for the action. 

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