Castles of the British Isles
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A castle is a fortified structure typically built during the Middle Ages, characterized by its defensive features and imposing appearance. It served as a residence for noble families, a symbol of power and authority, and a stronghold for military purposes. Castles were primarily constructed using stone or brick and consisted of various elements, such as walls, towers, gates, and courtyards.
The design of a castle was intended to provide strategic advantages in warfare, with features like thick walls, battlements, and moats. Towers, often located at the corners or along the walls, provided vantage points for defenders to observe and defend against potential threats. The main entrance to a castle was usually protected by a fortified gatehouse, which could include a drawbridge, portcullis (a heavy iron gate), and murder holes (openings in the ceiling to drop projectiles or pour boiling liquids on attackers).
Inside the castle, there were different areas for different functions. The keep or the central tower was the heart of the castle, serving as the lord’s residence and the last line of defense. It often housed living quarters, great halls for feasting, and other essential rooms. The castle could also have additional buildings for specific purposes like stables, kitchens, chapels, and storage facilities.
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How many castles are there in the British Isles?
The British Isles have a rich history of castles, and the exact number can vary depending on how one defines a castle. However, it is estimated that there are thousands of castles in the British Isles, encompassing England, Scotland, Wales, and Northern Ireland.
England alone is known to have had around 1,500 castles, although not all of them are still intact. Scotland also boasts a significant number of castles, with estimates ranging from 1,200 to 2,000 castles, including both intact structures and ruins. Wales, known for its impressive medieval fortifications, is believed to have had around 400 castles, although many are now in ruins.
In addition, there are numerous castles and fortifications in Northern Ireland, although the exact count is more challenging to determine.
The map below, created by Reddit user NeilParkinsonMakes shows the most famous castles of the British Isles.

Which castle is the most famous in the British Isles?
Windsor Castle (England)

The most famous castle in the British Isles is arguably Windsor Castle. Located in the county of Berkshire, England, Windsor Castle is the oldest and largest inhabited castle in the world. It has a history spanning over 900 years and has served as a royal residence for the British monarchs since the time of William the Conqueror.
Windsor Castle is renowned for its architectural grandeur, extensive grounds, and historical significance. It combines various architectural styles from different periods, including Norman, Gothic, and Victorian. The castle’s iconic Round Tower is a recognizable feature of its skyline.
Apart from being a royal residence, Windsor Castle is also a popular tourist attraction, drawing millions of visitors each year. It houses numerous art treasures, including paintings by renowned artists, ancient manuscripts, and a significant collection of royal artifacts. The State Apartments, St. George’s Chapel (the final resting place of several monarchs), and the changing of the guard ceremony are among the highlights for visitors.
Windsor Castle has been a favored retreat for British monarchs throughout history, and it continues to be an active royal residence today. Its combination of historical significance, architectural splendor, and royal connections has contributed to its fame as the most prominent castle in the British Isles.
Edinburgh Castle (Scotland)

While Windsor Castle is highly renowned, Edinburgh Castle is often also considered as the most famous castle in the British Isles. Located in the capital city of Scotland, Edinburgh Castle is an iconic symbol of Scottish history and heritage.
Perched atop Castle Rock, an ancient volcanic formation, Edinburgh Castle dominates the city’s skyline and offers panoramic views of Edinburgh. Its strategic location has made it a site of human habitation for thousands of years, with traces of settlements dating back to the Iron Age.
Edinburgh Castle has played a pivotal role in Scotland’s history, serving as a royal residence, a military fortress, and a place of royal ceremonies. It has witnessed numerous conflicts and sieges over the centuries. The castle houses several notable structures, including the St. Margaret’s Chapel (the oldest surviving building in Edinburgh), the Great Hall, the Crown Room (displaying the Honours of Scotland, Scotland’s crown jewels), and the Stone of Destiny, which was historically used for the coronation of Scottish monarchs.
The castle’s historical significance, stunning architecture, and cultural prominence have made it a major tourist attraction, drawing millions of visitors each year. The famous Edinburgh Military Tattoo, an annual event featuring international military performances, is held on the castle esplanade, further enhancing its fame.
Caernarfon Castle (Wales)

The most famous castle in Wales is Caernarfon Castle. Located in the town of Caernarfon in northwestern Wales, Caernarfon Castle is an impressive medieval fortress that holds significant historical and cultural importance.
Built by King Edward I of England in the 13th century as part of his campaign to assert English dominance over Wales, Caernarfon Castle served as a symbol of power and control. Its strategic location on the banks of the River Seiont and its imposing architecture make it one of the most visually striking castles in Wales.
Caernarfon Castle is renowned for its polygonal towers, fortified walls, and its distinctive Eagle Tower, which stands as a symbol of royal authority. The castle’s design incorporates elements of both military fortification and royal palace, reflecting its dual purpose as a stronghold and a residence for the English monarchy.
The castle has witnessed several significant historical events, including the investiture of the current Prince of Wales, Prince Charles, in 1969. Its connection to Welsh nationalism and its association with the Prince of Wales title have further cemented its cultural significance.
Caernarfon Castle attracts a large number of visitors who come to explore its battlements, towers, and inner courtyards. It is a UNESCO World Heritage site and forms part of the Castles and Town Walls of King Edward in Gwynedd, collectively recognized for their historical importance.
Blarney Castle (Ireland)

The most famous castle in Ireland is often considered Blarney Castle. Located near the village of Blarney in County Cork, Blarney Castle is a medieval stronghold that has gained worldwide recognition and popularity.
Blarney Castle is renowned for the Blarney Stone, which is said to grant the gift of eloquence to those who kiss it. The stone is set in the castle’s battlements, and visitors traditionally hang upside down to kiss it. This tradition has attracted countless tourists over the years, making Blarney Castle one of Ireland’s most visited landmarks.
The castle itself has a long history, with its origins dating back to the 10th century. The current structure was built in the 15th century and features a tower house surrounded by fortified walls and a beautiful garden. The castle offers visitors the opportunity to explore its various rooms, climb to the top for panoramic views, and enjoy the tranquil grounds.
Blarney Castle’s association with the Blarney Stone, its picturesque setting, and its blend of history and folklore have contributed to its fame. The castle and its surrounding gardens provide a unique visitor experience, combining medieval architecture, natural beauty, and the chance to participate in a well-known Irish tradition.
While there are many other notable castles in Ireland, such as Bunratty Castle, Ashford Castle, and Dublin Castle, Blarney Castle stands out as the most famous due to its iconic Blarney Stone and the global recognition it has received.
Which castles are the oldest in the British Isles?
Determining the oldest castles in the British Isles can be challenging due to various factors, such as architectural evolution, multiple phases of construction, and the definition of what constitutes a castle. However, here are some castles widely regarded as among the oldest in the British Isles:
- Colchester Castle (England): Built on the foundations of a Roman temple, Colchester Castle in Essex is believed to be the oldest surviving stone castle in Britain. It was constructed around the 11th century on the site of an earlier Roman fortress.
- Tower of London (England): The White Tower, the central structure of the Tower of London complex, was built by William the Conqueror in the late 11th century. It is one of the oldest parts of the tower complex, and its construction commenced around 1078.
- Rochester Castle (England): Rochester Castle in Kent, England, was founded shortly after the Norman Conquest in 1066. Its construction began around 1087, making it one of the earliest castles in England.
- Oxford Castle (England): Oxford Castle in Oxfordshire, England, has origins dating back to the 11th century. The castle was initially built as a motte-and-bailey castle by Norman baron Robert d’Oilly.
- Chepstow Castle (Wales): Chepstow Castle in Monmouthshire, Wales, was constructed by William FitzOsbern in the late 11th century. It is one of the oldest surviving stone fortresses in Wales.
Which castles in the British Isles have never been captured?
Several castles in the British Isles have impressive records of never being captured by force throughout their histories. Here are a few notable examples:
- Castle Sween (Scotland): Located in Argyll and Bute, Scotland, Castle Sween is believed to be one of the oldest stone castles in Scotland. It has a history dating back to the 12th century and has never been captured by siege.
- Harlech Castle (Wales): Harlech Castle in Gwynedd, Wales, is a medieval fortress built by Edward I in the late 13th century. Despite being involved in conflicts during the Wars of the Roses and the English Civil War, Harlech Castle remained impregnable and was never captured.
- Dunnottar Castle (Scotland): Perched on a cliff near Stonehaven, Aberdeenshire, Dunnottar Castle has a dramatic location and a reputation for being unconquerable. It successfully withstood numerous sieges and attacks throughout its history.
- Castle Campbell (Scotland): Castle Campbell, also known as Castle Gloom, is situated in Clackmannanshire, Scotland. Despite its strategic location and involvement in conflicts during the 16th century, it was never captured.
- Castle Rising (England): Castle Rising in Norfolk, England, is a well-preserved 12th-century keep that has the distinction of never being taken by force. It served as a residence and fortress but was never conquered during its active military period.
Which castles are the most unusual in the British Isles?
The British Isles are home to a variety of unique and unusual castles. Here are a few examples that stand out for their distinctive features or histories:
- Neuschwanstein-inspired Castle, Inveraray (Scotland): Inveraray Castle in Argyll, Scotland, is a remarkable example of Scottish baronial architecture. It was designed in the 18th century to resemble the fairytale-like Neuschwanstein Castle in Bavaria, Germany. With its turreted towers and romantic appearance, it stands out as a unique castle in the British Isles.
- Portmeirion Castle (Wales): Portmeirion Castle in Gwynedd, Wales, is part of the Italianate village of Portmeirion, which was created by architect Sir Clough Williams-Ellis. The castle, despite its appearance, is not a medieval structure but was built in the 20th century as part of the whimsical and eclectic village.
- Castell Coch (Wales): Located near Cardiff, Wales, Castell Coch is a 19th-century castle designed by William Burges. It is known for its vividly colored interiors, ornate decoration, and picturesque appearance. The castle’s romantic Gothic Revival style sets it apart from traditional medieval castles.
- Dunmore Pineapple (Scotland): While not a traditional castle, the Dunmore Pineapple in Falkirk, Scotland, is an unusual architectural structure. Built in the 18th century as a garden folly, it takes the form of a large stone pineapple atop a pavilion and is considered one of the most bizarre and unexpected architectural creations in the British Isles.
- Shell Grotto, Margate (England): Although not a castle in the traditional sense, the Shell Grotto in Margate, England, is a unique underground structure adorned with intricate mosaic patterns made entirely of seashells. Its origins and purpose remain a mystery, making it an intriguing and unusual site.