The United Kingdom is rich with historic castles, many of which offer stunning architecture, captivating history, and scenic locations. Here’s a list of some of the most famous castles worth visiting as a tourist:

1. Windsor Castle (England)

• Why visit?: The oldest and largest inhabited castle in the world and one of the official residences of the British monarch.
• Highlights: The State Apartments, St. George’s Chapel (where Prince Harry and Meghan Markle got married), the Changing of the Guard, and beautiful gardens.

2. Tower of London (England)

• Why visit?: A UNESCO World Heritage Site, this iconic fortress is known for its rich and sometimes grim history as a royal palace, prison, and execution site.
• Highlights: The Crown Jewels, the Yeoman Warder tours (Beefeaters), the White Tower, and stories of famous prisoners such as Anne Boleyn.

3. Edinburgh Castle (Scotland)

• Why visit?: Perched on a volcanic rock, Edinburgh Castle dominates the skyline and offers incredible views of the city.
• Highlights: The Scottish Crown Jewels, the Stone of Destiny, the National War Museum, and the One O’Clock Gun. It's also a focal point of Edinburgh's history, from royal battles to rebellions.

4. Warwick Castle (England)

• Why visit?: A medieval fortress with a history dating back over 1,000 years, offering a range of family-friendly activities and historical reenactments.
• Highlights: The Great Hall, the Castle Dungeon, the trebuchet (medieval siege weapon), and the War of the Roses live show.

5. Caernarfon Castle (Wales)

• Why visit?: A UNESCO World Heritage Site, this majestic castle is one of the most impressive in Wales and was the site of Prince Charles' investiture as Prince of Wales.
• Highlights: Its towering polygonal towers, vast defensive walls, and views over the Menai Strait. Walk along the battlements and learn about its military history.

6. Dover Castle (England)

• Why visit?: Known as the "Key to England," this coastal fortress has stood guard over the English Channel for centuries and played a pivotal role during WWII.
• Highlights: The Great Tower, the secret wartime tunnels, and panoramic views of the White Cliffs of Dover and the sea beyond.

7. Stirling Castle (Scotland)

• Why visit?: One of Scotland’s most important castles, associated with famous battles like The Battle of Bannockburn. It’s steeped in royal history.
• Highlights: The Royal Palace, the Great Hall, the views from the ramparts, and exhibitions on Scotland's royal heritage, including connections to Robert the Bruce and William Wallace.

8. Balmoral Castle (Scotland)

• Why visit?: The Scottish residence of the British royal family, purchased by Queen Victoria in the 19th century. It’s a working royal residence but open to visitors during certain months.
• Highlights: Beautiful Highland scenery, gardens, and exhibitions on royal life.

9. Alnwick Castle (England)

• Why visit?: Known for its stunning medieval architecture and its role as a filming location for Harry Potter and Downton Abbey.
• Highlights: Knight school, medieval reenactments, and Harry Potter-themed activities. The gardens are equally spectacular, including the Poison Garden and the Treehouse.

10. Leeds Castle (England)

• Why visit?: Often called the "loveliest castle in the world," this picturesque castle is set on islands in a lake and offers rich history and gorgeous gardens.
• Highlights: The maze, the grotto, the beautifully restored rooms, and the stunning grounds. It also offers falconry displays and boat trips.

11. Cardiff Castle (Wales)

• Why visit?: Located in the heart of Cardiff, this castle blends medieval fortifications with elaborate Victorian Gothic architecture.
• Highlights: The lavish Victorian interiors, the Roman fort ruins, and panoramic views from the castle keep.

12. Eilean Donan Castle (Scotland)

• Why visit?: One of the most photographed castles in Scotland, set on a small island where three sea lochs meet, it’s stunningly picturesque and steeped in Scottish clan history.
• Highlights: The dramatic setting, romantic history, and fascinating displays of the Mackenzie and MacRae clans.

13. Highclere Castle (England)

• Why visit?: Famous as the filming location for Downton Abbey, this grand estate offers insights into both real aristocratic life and the world of the Crawley family.
• Highlights: The lavish rooms, beautiful gardens, and exhibitions on the 5th Earl of Carnarvon's discovery of Tutankhamun’s tomb.

14. Bamburgh Castle (England)

• Why visit?: Located on the stunning Northumberland coast, it offers a mix of medieval and Victorian history, with amazing views over the sea and the Farne Islands.
• Highlights: The extensive grounds, views from the battlements, and exhibitions on the history of the castle and the local area.

15. Conwy Castle (Wales)

• Why visit?: A UNESCO World Heritage Site, this well-preserved fortress offers incredible views over the town of Conwy and the surrounding Welsh countryside.
• Highlights: Walking the castle walls, exploring the towers, and the sweeping views over the Conwy Estuary.

These castles provide a window into the UK’s rich history, from royal palaces to defensive fortresses. Whether you're interested in medieval battles, royal intrigue, or simply beautiful settings, there’s a castle for every kind of visitor! 

Here is a list of lesser known Castles that are worth the visit.

Here are some of the most famous and historically significant castles across England, but keep in mind there are hundreds, many of which have fascinating histories!

1. South East England

• Dover Castle (Kent) - Known as the "Key to England" due to its strategic location overlooking the English Channel.
• Leeds Castle (Kent) - Often called "The Loveliest Castle in the World," set on two islands.
• Windsor Castle (Berkshire) - The oldest and largest occupied castle in the world and a residence of the British monarch.
• Hever Castle (Kent) - Famous as the childhood home of Anne Boleyn.
• Arundel Castle (West Sussex) - A grand castle rebuilt in the 19th century, home to the Dukes of Norfolk.

2. South West England

• Tintagel Castle (Cornwall) - Linked to the legends of King Arthur.
• Corfe Castle (Dorset) - A thousand-year-old castle with a dramatic ruined appearance.
• Dunster Castle (Somerset) - A medieval fortress transformed into a Victorian country house.
• Bodiam Castle (East Sussex) - A picturesque, moated castle from the 14th century.

3. West Midlands

• Warwick Castle (Warwickshire) - A well-preserved medieval castle, now an interactive historical attraction.
• Kenilworth Castle (Warwickshire) - Famous for its connection to Elizabethan history and the Earl of Leicester.

4. East of England

• Framlingham Castle (Suffolk) - Known for its curtain wall and association with Mary Tudor.
• Hedingham Castle (Essex) - A Norman keep, remarkably intact.

5. North West England

• Lancaster Castle (Lancashire) - Historically used as a prison and linked to the Pendle witch trials.
• Penrith Castle (Cumbria) - The residence of Richard, Duke of Gloucester (later Richard III).

6. Yorkshire and the Humber

• Scarborough Castle (North Yorkshire) - Overlooking the North Sea, offering a dramatic cliff-top view.
• Skipton Castle (North Yorkshire) - One of the best-preserved medieval castles in England.
• Bolton Castle (North Yorkshire) - A 14th-century castle associated with Mary, Queen of Scots.

7. North East England

• Alnwick Castle (Northumberland) - The second largest inhabited castle in England, known as a filming location.
• Bamburgh Castle (Northumberland) - A striking fortress on the Northumberland coast.
• Durham Castle (County Durham) - Part of a UNESCO World Heritage site alongside Durham Cathedral.

8. East Midlands

• Belvoir Castle (Leicestershire) - A historic castle and residence of the Dukes of Rutland.
• Rockingham Castle (Northamptonshire) - Originally a Norman fortress, now a stately home.

9. Greater London

• Tower of London - A historic fortress and former royal palace, famous for housing the Crown Jewels.

10. Other Notable Castles

• Rochester Castle (Kent)
• Carisbrooke Castle (Isle of Wight)
• Berkeley Castle (Gloucestershire)
• Pevensey Castle (East Sussex)

Many of these castles are open to the public, with some offering tours, interactive exhibits, and special events throughout the year.