You're probably familiar with regal Windsor Castle or Germany's enchanting Neuschwanstein Castle. But there are plenty of underrated, yet equally impressive fortresses around the world with their own unique charm and fascinating history. Here we reveal some of the planet's most beautiful castles that you might not have known existed. 

Click through the gallery to see some of the world's most amazing lesser-known castles...

Crowning the island of Astypalaia, this gorgeous Greek castle sits on a hill overlooking the Aegean Sea. Constructed in the 15th century by Giovanni Querini, a Venetian official, the castle was built on the remains of the island's ancient acropolis to protect the town of Chora and its population. Today, rising high above Chora's white-washed Cycladic buildings, the Venetian castle is an impressive sight.

Perched atop a 160-foot (48.7m) rock and surrounded by the North Sea, these dramatic castle ruins are one of Scotland’s hidden treasures. The first stone castle at Dunnottar was built in the 14th century by Sir William Keith, the Great Marischal of Scotland. William Wallace, Mary Queen of Scots and King Charles II have all stepped through its doors. The castle is best known for protecting the Scottish Crown jewels during the war between Scotland, England and Ireland in the mid-1640s. Today, Dunnottar Castle is open to visitors.

Soaring above the Salzach River valley, this medieval rock castle is one of the most beautiful fortresses in Austria. It was built in 1077 under the orders of Archbishop Gebhard, alongside another fortress, Hohensalzburg. From being devastated by peasant revolts in the 16th century to being used as a prison in the 17th and 18th centuries, the castle certainly has a colourful history. Since 1987, Hohenwerfen Castle has been a much-loved tourist attraction and is regarded as one of Austria's most impressive landmarks.

Extreme geometric precision was used to create the impressive Castel del Monte, which can be found resting on a hill above the Murge plateau in Puglia. Commissioned by Frederick II around 1240, the castle has a perfect octagonal shape and is an incredible mix of Northern European and Islamic architectural elements. A UNESCO World Heritage Site since 1996, Castel del Monte is regarded as a unique piece of medieval military history.

Sitting on a large rock in the valley of the Our River, Vianden Castle is an impressive feudal residence from Europe's Romanesque and Gothic periods. The castle was built by the Hohenstaufen dynasty between the 11th and 14th centuries, yet during the 19th century, under the reign of King William I of Holland, the fortress was sold off in segments and eventually fell into disrepair. Since then, the castle has been restored to its former glory and is now a museum, hosting festivals and events throughout the year. 

Residing just outside of Brussels, this picture-perfect fortress is one of the oldest moated castles in the Flanders region. Originally dating back to 1310, Beersel Castle was rebuilt in the 15th century in the bold red brick common in most Flemish castles. With its massive watchtowers, drawbridge and wide moat, the castle played an important role in the region’s history as a defensive base. Since 1999, the castle has been undergoing extensive repairs and is a fine example of medieval architecture in Belgium. 

Duart Castle is surrounded by some of the most spectacular scenery of Scotland’s west coast. Sitting on a high crag that overlooks the Sound of Mull, the castle has served as the ancient seat for Clan MacLean, one of the oldest clans in the Scottish Highlands, for more than 700 years. Today, visitors can discover MacLean's history in the castle's lavish state rooms and Great Hall. Duart Castle is one of the last surviving privately owned clan castles in Scotland.

Love this? Follow our Facebook page for more travel inspiration

Some may be surprised to discover that America also has its fair share of castles. Named after its designer, actor William Gillette who is best known for playing Sherlock Holmes, this unique medieval-style castle sits atop one of the Seven Sister Hills above the Connecticut River. Completed in the early 20th century, the castle took five years to build. Now open as a visitor attraction, it's filled with artefacts, documents and architectural details that offer an insight into Gillette’s eccentric personality and colourful tastes.

Discover the secrets of the world's most incredible castles and palaces

Looming on a hill high above the Danube Valley, Clam Castle has been lived in by the Counts of Clam for over 550 years. The earliest mention of the castle dates back to the 12th century, but it wasn’t until 1454 that the Counts of Clam took over the castle, defending it during the Thirty Years' War with their private army. Visitors can follow in the footsteps of these historical figures throughout the castle: the vast estate includes forests, farmland and a riding school. 

Kilkenny has a long, 800-year-plus history, established as it was in the late 12th century, after the Norman Conquest. A jewel of its namesake city in Ireland, it's changed a lot over the years, having been transformed by various owners – as it stands today, it's predominantly a Victorian remodel of its 13th-century state. Now, hundreds of thousands of people flock to Kilkenny Castle every year to enjoy its incredible rooms, landscaped gardens and trails. 

Teetering on a rocky outcrop, Caccamo Castle can be found at the foot of Monte San Calogero overlooking the village of Caccamo in Italy. The impressive fortress was originally built in the 12th century by Norman knight Matthew Bonnellus, before being extended in the early 14th century. Inside, there's a labyrinth of rooms, while its boxy towers give it an imposing feel – stunning views across the San Leonardo River valley from the hill make the spot truly unique.

Known as the longest fortress in the world, Burghausen Castle trails for a whopping 3,348 feet (1,051m) across Upper Bavaria. Guarding its namesake town, a stone complex is thought to have existed here since the 11th century, built by the counts of Burghausen. Throughout its long life, Burghausen Castle has changed multiple hands and has been extended and modernised numerous times. Today, with its strong walls, large moat, great halls and nearly all of its fortifications still intact, Burghausen Castle is one of the greatest medieval fortresses on Earth.

Built onto a sheer rocky crag in northwest Wales overlooking the Irish Sea, this mighty coastal fortress is as dramatic as they come. Harlech Castle was built in the 13th century by King Edward I of England and took seven years to complete. Despite its strong fortifications, the castle has a tumultuous past, subjected to rebellion, sieges and wars. Today, Harlech Castle, along with Beaumaris Castle, are a designated UNESCO World Heritage Site, recognised for being a well-preserved example of military architecture during the reign of Edward I.

Located in Kanazawa, this charming castle in Japan was the residence of the powerful Maeda family for hundreds of years. The first feudal lord Maeda Toshiie entered Kanazawa Castle in 1583, and it has been rebuilt and remastered ever since. The castle has been badly damaged by multiple fires, and the longest surviving features are the Ishikawa-mon Gate and the Sanjikken Nagaya, an armoury rebuilt in 1858. Now a designated National Historic Site, the castle has regained its status as a proud symbol of the city's heritage.

Known as one of the oldest fortresses in Spain, Loarre Castle is among the country's best-preserved Romanesque fortresses too. Sitting between the Ebro River valley and the Pyrenees mountains, Loarre Castle was built in the late 11th century under the orders of King Sancho Ramírez I of Aragon. With over a thousand years of history to its name, the castle is teeming with historic treasures, including its formidable double walls, arched windows and the incredible church of Santa María.

Check out more of Europe's most beautiful castles

Situated just outside of Utrecht, De Haar Castle is the largest fortress in the Netherlands. With its ramparts, moat and drawbridges, the castle may look medieval, but it was actually finished in the early 20th century, envisioned by the famous Dutch architect Pierre Cuypers. A hub for the rich and famous, the castle has hosted plenty of celebrities and notable figures including Coco Chanel and Roger Moore. It was also formerly the private residence of the Van Zuylen family. Today, the family resides in the castle one month per year as per tradition, while for the rest of the time, it's open for the public to enjoy.

Set in the heart of historic East Sussex, with its impressive fortifications and beautiful facade, Bodiam Castle is one of England’s most picturesque fortresses. The castle’s history begins in 1385 when it was first built by Sir Edward Dalyngrigge to protect the area of East Sussex from the French during the Hundred Years' War. Now owned by the National Trust, Bodiam Castle has become a Grade I-listed landmark that hosts a range of family-friendly events and activities throughout the year.

Soaring high above the town of Untergruppenbach, the grand and mighty Stettenfels Castle is hard to miss. Built in the 11th century, the castle was once owned by the Fugger family and has also passed through the hands of several dukes. An important stronghold during the Middle Ages, it's now used for various cultural events and can be rented out for private occasions. The castle also hosts a popular medieval festival each year, with activities including jousting tournaments, traditional music and crafts.

With origins in the 13th century, the beautiful Caetani Castle watches over the medieval village of Sermoneta. The castle was built by the Annibaldi family, before it was passed into the hands of the Caetani family in 1297 who expanded the estate. Over its history, Caetani Castle has held plenty of lavish celebrations for emperors, cardinals, princesses and more. The Caetani family were excommunicated in 1499, and it wasn’t until the 19th century that the family returned to the castle, transforming it into a social and educational centre.

Nestled on the shores of Lake Malar, Gripsholm Castle proudly looks over the small town of Mariefred in southeast Sweden. Formerly the official residence of Renaissance Prince Gustav Vasa, the castle was built in 1537 as part of Sweden's new defensive system. With a history spanning five centuries, the castle is filled with historic rooms and artefacts that offer a window into the past, including Gustav III’s theatre and the Swedish National Portrait collection.

This foreboding fortress stands over the medieval town of Medina del Campo. Built in the 15th century under the orders of King Juan II of Castile and his family, the La Mota Castle was mostly used as a fortress, but also doubled as a strategic military base. The castle was also a prominent prison during its lifetime, with notable inmates including political figure Cesare Borgia and Spanish conquistador Hernando Pizarro. Today, La Mota Castle offers guided tours throughout the grounds and is also used for conferences, courses and cultural activities.

Situated in south-central Sweden, Orebro Castle has been a site for important meetings and celebrations since the late 14th century. The exact origins of the castle are unknown, although it's thought that the oldest part, the defence tower, was built in the late 13th century. The castle was extended during the reign of the royal Vasa family (1523-1654) into a Renaissance masterpiece. Refurbished several times since then, the castle has now been transformed into a popular attraction and visitors can explore its history through exhibitions, guided tours and films.

With its twin-towered gatehouse, this magnificent castle on the southern coast of Scotland is the perfect medieval stronghold. First built in the 13th century by the Maxwell family, Caerlaverock Castle was besieged by Edward I during his war against the Scottish King John in 1300. The castle is best known for its triangular shape, which is unique among British castles. Surrounded by a double moat and unspoilt countryside, it's one of the most impressive fortresses in the country. 

Central Park, New York City’s most famous green space, is home to plenty of delights, and they include its very own miniature castle. In the heart of the park, adorable Belvedere Castle is perched on top of a vast rock outcrop known as Vista Rock. Completed in 1872, it was built as a place to enjoy views of the surrounding landscape. Today, it also houses one of the park’s visitor centres and a gift shop.

Lying on an islet in the middle of the River Tagus, Almourol Castle is one of the most enchanting fortresses in Portugal. A castle already existed here before it was taken over by Christian knights in 1129 and given to Gualdim Pais, leader of the Knights Templar. The castle became part of a series of defenses along with the castles of Tomar, Cardiga and Zezere. After the Knights Templar were disbanded, Almourol Castle lay abandoned until it was restored during the Romanticist movement in the 19th century. Today, the castle serves as a striking reminder of the Christian reconquest.

Another typical English castle, this mighty Northumberland fortress sits high on a hilltop above the River Coquet in northern England. Thought to have been built in its current state in the 1200s, the castle was the main home for the Percy family – one of the most powerful noble families in the region – between the 14th and 17th centuries. Today, along with the remains of a chapel known as the Hermitage, which also lies on the riverbanks, the ruined medieval castle has become a much-loved historic site.

Loket Castle is the most visited attraction of the charming town of Loket, which lies in the west Bohemia region of Czechia. Rising above the pretty Ohre River on a rocky promontory, the 12th-century castle looks like it’s straight from a fairy tale. Built in a Romanesque-Gothic style, the castle served as a temporary residence for members of the royal family. Following its reconstruction in the late 20th century, the castle opened to the public as a museum that includes an exhibition on torture, historic weapons and Gothic murals.

Towering above the town of Trencin in Slovakia, Trencin Castle can be traced back to the 11th century. For hundreds of years, the fortress has protected important trade routes linking the region of Northern Ugria and the mining towns of Central Slovakia with other regions including Bohemia and Moravia. Now, it's open to the public and exhibition rooms detailing the castle’s history and expositions from the Museum of Trencin can be found within its stony walls. 

Crowning a rocky islet at the northern end of the Gulf of Naples, this dramatic castle is celebrated for its rugged beauty. Originally named Castrum Gironis, the castle is thought to date back to at least the 5th century BC, though its current name and appearance came from Alfonso I of Aragon in the 15th century. Connected to Ischia Island by a small stone bridge, and with its dramatic facade set against the beautiful blue waters of the bay, Aragonese Castle feels like its own little world and is easily one of the most impressive sights in Ischia.

Jutting out on a tiny peninsula near the Bort-Les-Orgues reservoir in France, the Chateau de Val resembles a romantic painting. Built in the Middle Ages for defensive reasons, the castle used to rise over the valley of the Dordogne River. Then the dam opened, flooding the valley and creating the enchanting scenes of today. One of the finest and best-preserved buildings in Auvergne, the dreamy castle has become a must-visit tourist attraction in the region.

Overlooking the English south coast, Dorset's Highcliffe Castle is the stuff of fairytales. Since the 19th century it's been home to lords, Major Generals and even a Canadian opera singer, but today the public can venture around its restored Drawing Room, Great Hall and Library plus more. Its striking architecture features Romantic, Picturesque and Gothic Revival styles and was partly constructed using stones lifted from ruined abbeys in France. It's now a popular wedding venue, complemented with a stunning backdrop of the sea.

To call the Amber Fort (also known as the Amer Fort) a castle is to downplay it somewhat. The magnificent and extensive palace complex, built atop a hill just under seven miles (11km) from one of India's most beautiful cities Jaipur, combines pale yellow and pink sandstone with white marble in a manner that's sure to steal your heart. Built in the 16th century by Raja Man Singh I, this truly staggering architectural structure is divided into four main sections that are each graced with their own courtyards. Done with the epic views? Head underground and explore the tunnels.

Nestled between the breathtaking blue of the Coral Sea and the mountainous Tablelands of northern Queensland, surrounded by vivid green, you'll find the strange Spanish castle of Paronella Park. Jose Paronella, an immigrant from Catalonia, made his fortune in Australia's early 20th-century sugar cane industry. The romantic story goes that Jose had dreamed of building a castle and garden in honour of his wife Margarita, but it's also been said this place was created as a symbol of personal triumph. Whatever the truth, it's an idyllic spot.

Completed in 1908, Hatley Castle is situated on the grounds of Hatley Park and Royal Roads University on Vancouver Island. A mixture of local stone, Valdes and Saturna Island sandstone was used in the building's construction. The grandeur of its exterior is matched by the lavishness of its interior, with oak and rose panelled rooms combining wonderfully with teak floors and luxurious light fittings. James Dunsmuir, who commissioned the architect responsible, is quoted as saying: "Money doesn't matter, just build what I want."

Built by the Dutch East India Company between 1666 and 1698, the Castle of Good Hope is South Africa's oldest existing colonial building. Following extensive restoration work in the 1980s, the bastion fort in Cape Town was returned to how it would have looked when it was first constructed. You'll be hard pressed to find a better-preserved piece of 17th-century architecture anywhere in the world. That view of Table Mountain in the background isn't bad either.

Now discover the secrets of the world's most beautiful mountains