From its mainland and offshore islands to its waters, Australia is teeming with wildlife, much of which you won’t find anywhere else on the planet. To that end, our team of well-travelled experts have ranked the country’s most amazing wildlife experiences, from spotting dozing koalas, swimming next to a whale shark or walking alongside waddling wombats.

Click through the gallery to see which unique Australian wildlife experiences to add to your Oz bucket list…

Watching mating cuttlefish might sound peculiar but this is one of Australia’s most incredible aquatic spectacles. Each winter thousands of giant Australian cuttlefish congregate along a six-mile (10km) stretch of the Upper Spencer Gulf Marine Park off the coast of Whyalla.

The peak time to see the world’s largest cuttlefish in action is June and July. You can see them shape-shift and colour-change to attract mates. The females then lay and attach their eggs to the rocky seashore.

Slip on your wetsuit and snorkel (or dive) gear and get under the waves in the waters around Point Lowly and Stony Point (AKA the Cuttlefish Coast) to see these mesmerising mating scenes. Keep a safe (and respectful) distance, naturally.

South Australia’s display is significant because it’s the only place on Earth that giant cuttlefish congregate annually on such a scale and with such predictability. Beware, though: the water is nippy so if you’d rather stay warm and dry, hop on a glass bottom boat tour instead.

Lying just off Narooma on the state’s far southern coast, Montague Island Nature Reserve is home to one of the country’s largest colonies of Australian and New Zealand fur seals, along with sea lions and 90 species of bird.

You can see these 'puppies of the sea' at play on shore and in the water during a guided snorkel tour of the uninhabited island’s sheltered bays. Expect clear waters and to fall head over heels in love with these playful and inquisitive creatures. 

Go shortly after December and you may also spy baby seal pups. If you can tear your eyes away from the seals, you’re also likely to see Port Jackson sharks (pictured), wobbegongs, stingrays, bull rays and blue groper.

If you’re on the island between September and November, a whale watching excursion is a must. The NSW coast is known as ‘Humpback Highway’ and these giants, along with southern right and pilot whales, migrate along the coastline in large numbers, swimming incredibly close to Montague Island.

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Out of all Australia’s endearingly odd animals, the platypus is by far the most curious. Getting a glimpse of the amphibious monotreme (egg-laying mammal) can prove challenging, however.

The lakes and rivers of Tasmania have some of the best spots for seeing them, most notably the Warrawee Forest Reserve on the Mersey River (just outside the northern Tassie town of Latrobe). In fact, it's known as the top place in the whole country for spying the elusive platypus in the wild.

Go at dawn or dusk to optimise your chances of seeing the animal and wait patiently (and quietly) near the riverbank until ripples appear. Then follow these ripples to (hopefully) see the little duck-billed creature come up for air.

As platypus are nocturnal hunters, the very best times to spot them are just before sunset when they emerge from their burrows and around 30 minutes after sunrise when they head back in.

Killer whales or orcas are more commonly associated with the frigid waters of the Arctic and Antarctic, but the apex predators (which are members of the dolphin family) also frequent Australia’s waters.

The orcas gather to feed in the waters off Bremer Bay in Western Australia from December to April. Highly intelligent and social, orcas move in family pods and work as a team to hunt fish, seals, dolphins, sharks, whales and squid, making them powerful and skilful predators. 

Set sail from Bremer Bay Boat Harbour onboard Naturaliste Charters’ luxury catamaran for an eight-hour expedition to see the mighty marine mammals at play in the Southern Ocean. You’ll be accompanied by a marine biologist and photographer as you go in search of orcas. If you don’t spot any, you can head out on another tour for free.

Keep watch for long-finned pilot, blue and rare beaked whales too. Bottlenose, striped and common dolphins will likely make an appearance and you may spot the dorsal fins of other apex predators like great white sharks.

Queensland’s Great Barrier Reef offers a dazzling array of marine encounters with something new to spot on every dive or snorkel. But have you ticked off the 'Great Eight'? Head off on snorkel tours or dives to see if you can spot them all.

The big hitters of the reef are clown fish, giant clams, manta rays, Maori wrasse, potato cods, sharks (white tip, black tip and grey reef), whales and six turtle species.

Dive boats depart from resorts along the Coral Coast and from its islands, but there’s a whole host of other ways to enjoy the underwater wonders if you don’t want to get deep down.

You can snorkel straight off the beaches of sheltered islands, go out on glass bottom boat tours or semi-submersibles and step into underwater observatories. You can even bed down for the night in an underwater hotel room, Reefsuites.

Witnessing the dawn chorus in Kakadu’s wetlands is quite an experience and a noisy one at that. The national park has more than 280 different types of birds, around a third of all species in Australia.

The tropical summer is the time to see the park’s waterbirds at their liveliest. Brolgas, jabirus, egrets and comb-crested jacanas are all there while you may spy white-bellied sea eagles soaring over the billabongs before swooping down to scoop up fish in their claws. 

A sunrise cruise on the Yellow Water (Ngurrungurrudjba) wetlands, home to at least 60 bird species, is the best way to immerse yourself in the cacophony of the dawn chorus. You’ll also spy crocodiles lurking in water and water buffalo grazing on the floodplains.

Visit from late August to late October and you’ll see thousands of magpie geese arrive in the wetlands. These magnificent waterbirds were a traditional bush food for Kakadu’s Aboriginal owners. Keen ornithologists should time their visit with Kakadu Bird Week for specialist lectures and cultural events.

A relative of the seahorse, the curious leafy sea dragon is endemic to the southern waters of Australia. You can admire the creature's leaf-like appendages and long dragon-esque snouts in various places around the coastline.

One of them is the Rapid Bay Jetty dive site in South Australia’s Fleurieu Peninsula. The bay's dilapidated old jetty is home to a healthy population of the protected species and is one of the prettiest shore dives in the country.

Book a tour with Dive Adelaide to get right up close to these elusive marine creatures. Over the course of two dives from Rapid Bay’s new jetty, you’ll swim across to explore the old jetty’s overgrown pylons. The incredible masters of disguise, which gently float in sea grasses, can be hard to spot at first but you’ll soon spy them.

You’re also likely to spot colourful cuttlefish (pictured), soft corals, sponges, leatherjackets and cowfish in the water.

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Queensland is Australia’s top turtle watching spot – it's home to six of the world’s seven species. Head to Mon Repos Conservation Park in Bundaberg which has the largest population of nesting marine loggerhead turtles in the South Pacific.

You can join park rangers to see the endangered marine turtles nest and hatch. The females haul themselves up the sands here every November to January and lay around 150 eggs before heading back to the ocean. The tiny, determined hatchlings then emerge between January and March. 

The turtles' extraordinary breeding pattern sees the creatures return to the very same beach that they hatched on decades before. Another top spot to admire these endangered marine animals is the coral cay Lady Elliot Island in the southern Great Barrier Reef.

Both green and loggerhead turtles nest here from November to February, and you can see the tiny turtles scurrying across the sands to safety from February to April. It’s also a great place to snorkel with manta rays.

Home to the world’s southernmost coral reef, far-flung Lord Howe’s waters are full of aquatic wonders by day and night. Head out to explore the reef when the sun dips down to get a different (and exhilarating) perspective on what goes on below the waves.

With fringing coral reefs just offshore, a huge diversity of fish, coral and algae can be seen by snorkelling just a short distance from the beaches.

Many of the reef's inhabitants are more active at night and this is also the time to see the extraordinary coral fluorescence. While it can be unnerving to swim in the dark, go with a guide and you’ll be in good hands.

A summer-only tour takes people out on a glass bottom boat with snorkelling equipment and underwater torches included. Illuminated boundary markers ensure snorkellers navigate their way around the site and don't stray from the group. Prepare to be amazed by the psychedelic displays of colour you'll see on your three-hour aquatic adventure. 

Get snap happy on a guided boat tour of Mary River wetlands and floodplain (just west of Kakadu National Park) where fearsome yet fascinating saltwater crocodiles lurk. The area has the world’s highest concentration of salties, along with an array of birds.

Cruise around the stunning Corroboree Billabong, edged by flowering pink lotus and water lilies, to learn about the region’s birds and get close to the prehistoric predators.

Sunrise is a stunning time of day for meandering around Mary River's waterways, when the sun casts a dazzling display over the landscape and the birds start to busy about. But while you’ll see plenty of log-like forms in the water, it’s not the best time to see crocs basking on the banks.

Late afternoon is prime time to see salties in all their glory as they’re at their most active just before dark, preparing for a night of hunting. You’ll also get to see the sunset paint its vivid colours over the floodplains.

You’ll be spellbound by more than the sweeping Southern Ocean vistas, white sands and striking rock formations on a two-day wildlife tour of Kangaroo Island with the Exceptional Kangaroo Island tour company.

Led by a wildlife expert, Exceptional Kangaroo Island takes you on a tour exploring the biodiverse island's tall eucalyptus forests to see snoozing koalas and into native bushland on the north coast where kangaroos, tammar wallabies, short-beaked echidnas and possums roam. 

Venturing along the striking coastline you’ll have a private tour of the island’s Seal Bay Conservation Park, where Australian sea lions laze on the beach and play in the water. You can get within steps of these rare marine mammals.

A stroll around Flinders Chase National Park reveals the island’s dramatic rock formations too, including Remarkable Rocks and Admirals Arch, where long-nosed fur seals hang out.

A former penal colony turned nature reserve, little Maria Island sits just off Tasmania’s east coast and is home to an astonishing amount of native wildlife.

Take the Maria Island Walk, which circuits around white sand beaches, up towering peaks, along sheer cliffs and into its blue and white gum forests, and you’ll observe more than a few chubby wombats wandering beside you. The island is home to a plentiful population of the rotund marsupials, who are at their most active at dusk.

As well as being enchanted by the world’s largest burrowing mammal, you’ll spy many other incredible creatures over the course of this four-day walk. Tasmanian devils, Forester kangaroos, Bennett’s wallabies, pademelons and 125 bird species – including 11 of the state's 12 endemic birds – also inhabit the wild little isle.

The surrounding waters are rich in marine life too, from fur seals to dolphins.

Swimming next to the largest fish in the ocean is an extraordinary experience and Ningaloo Reef is one of the best places on the planet to do it. The beautiful spotted creatures, which are in fact filter-feeding sharks, arrive on the western coast of Australia to feed between March and July every year, following a mass annual coral spawning.

Ningaloo is Australia’s largest fringing coral reef and whale shark tours depart from the towns of Coral Bay and Exmouth.

You’re pretty much guaranteed to get up close to these docile creatures as tour operators use spotter planes to locate the whale sharks, before boats stop a safe distance from them. A dive master takes small groups into the water to swim above the distinctive fish, which can reach up to 39 feet (12m) in length, as they glide along below.

You’ll see an array of coral, reef fish and turtles too as most tours include a few snorkel stops on the reef as well. At other times of the year you can swim with manta rays and humpback whales here.

Spot koalas in the crooks of gum trees; mobs of kangaroos and stalking emus on grasslands; plus long-nosed potoroos and bandicoots foraging on forest floors on guided nature walks.

Wildlife Wonders is a new wildlife sanctuary on Victoria’s scenic Great Ocean Road, designed by Brian Massey, landscape designer of New Zealand’s Hobbiton. It immerses visitors in the Otway region’s native flora and fauna with its conservationist-led walks.

The animals live freely in this natural setting, bound by fox-and-cat-proof wire to keep predators at bay. Go for a 75-minute daytime stroll through its native tree fern gullies and eucalyptus woodlands. Or get there for dawn and dusk, which are some of the best times to see the reserve’s most elusive creatures, like the tiny sugar glider.

During these 120-minute tours you can also watch the sunrise over the Southern Ocean or set behind the Otway Hills. All funds go to support conservation and research programmes in the region.

There’s no real surprise with our number one pick, the quokka. Dubbed the world’s happiest animal because of their sweet little smiles, quokkas only live on Rottnest Island, a 30-minute ferry ride away from Perth.

The small marsupials roam freely on the car-free nature reserve with its white-sand beaches, turquoise bays and coral reefs. They can be found almost anywhere, so you’ll soon stumble upon one, but Thomson Bay (or the Settlement) is a failsafe place to start your search.

A type of small wallaby, the quokka is mainly nocturnal but can be seen resting or sleeping in the shade during the day. Hire bikes to follow cycle paths around the island to seek out the animal and discover the stunning habitats that they, and many other critters, call home, from limestone heaths and woodlands to wetlands and beaches.

You can also join a free guided walk. And from March to August, you might also see young joeys peeking out from their mothers’ pouches.

Now take a look at 40 of Australia's most stunning natural wonders