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There are so many awe-inspiring castles in South Wales that this list was difficult to compile. The region is full of castles because of the strategic links it offered to the border between England and Wales which for a long time was a great source of conflict.

For this reason, many of these castles provide fine examples of defensive fortresses designed to keep out the invaders. In this guide, I’ll share 16 of the top castles in South Wales that you should consider visiting, along with a few notable mentions too.

1. Cardiff Castle

An article on the best castles in South Wales would certainly not be complete without the mention of Cardiff Castle. Located in the heart of the capital, Cardiff Castle offers a jam-packed family day out. Complete with its own Norman Keep and preserved Roman walls this Castle has something for everyone.

You can walk through the tunnels which were used as air raid shelters, as well as explore the Victorian apartments. If you fancy a bit of fresh air you can visit Castle Square which has access to the Cafe and public toilets for free!

If you want more information or need help planning your visit, go to our dedicated page for visiting Cardiff Castle

2. Chepstow Castle 

Located on the Welsh-English border this 600-year-old fortress is beautifully preserved. It stretches out across a hilltop overlooking the River Wye and is truly magical. Chepstow Castle was one of the first Norman strongholds in the country so has a legitimate claim as the oldest castle in Wales.

It was built in 1067 by Earl William fitz Osbern who was a close friend of William the Conqueror. The Castle was then owned by a number of extremely wealthy men including William Marshal (Earl of Pembroke), Roger Bigod (Earl of Norfolk) and Charles Somerset (Earl of Worcester).

Each of these owners left his own stamp on the Castle until it was left to decline after the Civil War. Today the Castle sits as a ruin, however, it is not hard to imagine the grandeur this Castle would have expressed at its height. 

3. Dinefwr Castle 

Dinefwr Castle sits atop a hilltop overlooking the Tywi Valley. Although the Castle is now a ruin, it once played an important role in Welsh history. First constructed in the 12th century, the Castle was owned by The Lord Rhys who was ruler of the ancient south Wales kingdom of Deheaubarth.

His reign, unusually for the time, was characterised by peace and stability where Welsh music, culture and poetry thrived. As can be expected, however, this did not last and as Wales fell into conflicts over succession after Rhy’s death, the Castle experienced instability.

The Castle eventually fell into the hands of the English in 1287 and the Welsh did not manage to reclaim it for centuries. The famous Welsh rebel Owain Glyndwr attempted to take the Castle back during his uprising in 1403, however, he was unsuccessful.

Today, you can visit the ruins of this castle where you can climb up the round tower, explore the keep, and walk along the curtain wall for panoramic countryside views.

4. White Castle 

White Castle is one of the best preserved of the three castles in Monmouthshire known as ‘The Three Castles’. These castles (see the other two below) were constructed to control the border with England.

White Castle would have originally been constructed from wood and earth but a series of later renovations led to its appearance in stone today. There are theories that its name has come from the white render that would have been used on its masonry at one time.

The Castle’s structure is made up of an outer ward and an inner ward. The former is the size of a football pitch and the latter is a pear shape and hides behind a steep, water-filled moat. King Edward I took possession of the Three Castles in 1254 and it is thought that these defences were his additions to the Castle.

This was his first Welsh castle and it is thought White Castle in South Wales provided the inspiration for his mighty fortresses across the rest of the country.

5. Skenfrith Castle

Another of ‘The Three Castles’ founded by the Norman lord William fitz Osbern in the 12th century is Skenfrith Castle. The remains that can be seen today are of the 13th-century fortress constructed by Hurbert de Burg.

The walls of the Castle are well preserved and surround a circular keep. The structure was built on an earthen mound to provide extra defences if it were attached.

Combined ‘The Three Castles’ covered and controlled a large area of the border between the River Wye and the Black Mountains. Furthermore, with its position on the banks of the River Monnow, Skenfrith overlooks the main routes between Wales and England. 

6. Grosmont Castle

The third member of ‘The Three Castles’ is Grosmont Castle. Also built by the Normans in order to control the border between England and Wales. Like the other two castles in this trio, it would have originally been made from earth and timber which would later be replaced with stone.

It also sits atop a hill for a vantage point looking out across this troublesome part of the country. In the 13th century, the gatehouse and circular towers were added. In the 14th century, apartments were added for the nobleman and his household. In the 15th century, Grosmont was besieged during the rebellion of the famous Welsh rebel Owain Glyndwr.

7. Caerphilly Castle

Caerphilly Castle is one of the best castles in Wales. not only is it steeped in history, but it’s Wales’ biggest castle and the second largest in Britain, beaten only by Windsor Castle in size. The Castle was defended by 30 acres worth of water defences as well as its massive walls, towers and gatehouse. In fact, the Castle is so large it is three times the size of the Principality Stadium.

The medieval fortress was constructed in 1268 by Marcher lord Gilbert de Clare in order to counter the rise of the powerful Prince of Wales.After the death of Llywelyn ap Gruffudd, this fortress which once sat on the frontline was transformed into a palatial home complete with a hunting park and lake.

It then passed into the hands of Hugh Despenser who was Edward II’s ruthless and greedy favourite. Dispenser revamped the great hall and finished them in an ornate style.

The Civil War left a lasting physical mark on the Castle. The southeast tower has been left angled precariously due to attacks during the conflict and is often referred to as Wales’ equivalent to the leaning tower of Pisa.

Thinking of visiting? See my full Caerphilly Castle visitors guide to plan your trip.

8. Llansteffan Castle 

Llansteffan Castle offers the most spectacular views from its ruined walls. It overlooks farmland, the sea and the sandy banks of the Tywi Estuary and Carmarthen Bay.

The Castle was originally constructed here in the 12th century because of these sweeping views. Its proximity to the river meant it could control an important river crossing. The 12th-century walls enclose an Iron Age fort which was occupied in 600 BC.

Eventually, a double bank and a ditch were constructed across the neck of the headland on which the Castle sits to create a defensive promontory fort. It is no surprise, therefore, that when the Norman invaders came across the fortress, they recognised its importance and defensive advantages.

Its large twin-towered gatehouse was constructed in around 1280 and can still be visited today.

9. Kidwelly Castle

Kidwelly Castle is another Norman stronghold and sits above the River Gwendraeth. Kidwelly may be particularly recognisable as it features in the very first scene of ‘Monty Python and the Holy Grail.’

When it was first constructed in the 12th century, it was a Norman ‘ringwork’ castle made of wood. Its defences were made up of just an earthen bank and ditch. It was therefore under constant attack from the Welsh Princes and was captured in 1159 by Lord Rhys.

By the 1280s the Norman Chaworth brothers who were powerful English lords, created the concentric ‘castle within a castle’ design we see today. At this point, the Castles defences were made up of a drawbridge and portcullis, arrowslits in the outer wall and four towers on the inner wall.

It was therefore almost impossible to conquer without extreme bloodshed, even Owain Glyndwr could not break through. Throughout the rest of its history, the Castle see-sawed between Norman and Welsh control.

10. Castell Coch

Castell Coch or the ‘Red Castle’ sits within Fforest Fawr near Cardiff and can easily be visited on a day trip. Designed by the architect William Burges under the supervision of the extremely wealthy Marquess Bute, the interior of the castle was decorated with extravagant furnishings.

In the High Victorian era, this castle is what’s known as a folly. Follies were extremely popular in the Victorian era and were buildings, homes and hunting lodges constructed to look like an original medieval castle.

However, behind this lavish Victorian folly lies the remains of a 13th-century castle which was once the hunting lodge of Marcher lord Gilbert de Clare. 

11. Oystermouth Castle

Sat atop a hill overlooking the picturesque village of Mumbles in Swansea, Oystermouth Castle is a beautiful castle to visit.

The earliest building on the site is the keep which dates from the early 12th century. The Castle was used as the residence of the Marcher Lords of Gower and was frequently under attack from local Welsh rebels.

During the 12th century, the Castle was used by the first Earl of Warwick and his family and then in 1203, the lordship of Gower was given to the de Breos family until 1230 when it passed to the de Mowbray’s. The de Mowbray’s lost Gower to the Beauchamps due to a legal decision and then in 1461 it passed to the Herberts, the Somersets and then to the Dukes of Beaufort1 (source: Swansea Council).

The Castle was held by the latter until 1927 when it was transferred to Swansea Corporation. 

12. Raglan Castle 

© Crown copyright (2022) Cymru Wales

This medieval castle was built by Sir William ap Thomas the ‘blue knight of Gewnt’ in the late 15th century. He is said to have built the moated Great Tower at Raglan Castle in 1435 which still stands today.

His son, Sir William Herbert, Earl of Pembroke then took over the castle after his death and created the gatehouse. The gatehouse contains flared ‘machicolations’ these are stone arches which would have allowed missiles to be thrown down at attackers.

The castle really became the staggering fortress we see today later than this when it came into the ownership of various earls of Worcester. These men transformed the castle into a country seat with a long gallery and an impressive Renaissance garden.

Raglan would also play an important role in the English Civil War when it fell to parliamentary forces after one of the longest seiges of the war2 (source: CADW).

13. Coity Castle

Whilst all that remains of Coity Castle are its ruins, the structure is still just as imposing as other, more complete castles on this list. The Castle was originally constructed in the early 12th century but it was renovated and added to continuously throughout its long life and so the remains today are a jumble of architectural styles.

The Castle’s life began in 1100 as an earthwork castle. Then in the 12th century, a stone keep and curtain wall were added. Major work was done during the 14th century and then again in the 15th century after a siege of the Castle by Owain Glyndwr during his uprising against the English in Wales. A third floor was added in the 16th century alongside other modifications. 

14. Margam Castle

Margam Castle is like something out of a fairytale. This 19th-century Gothic Mansion was designed by architect Thomas Hopper for Christopher Rice Mansel Talbot. The Grade I listed mansion was constructed in 1830-40 and cost £50,000.

The Castle remained in the ownership of the Talbot family until 1942 when it was acquired by the local landowner, Sir David Evans Bevan. The Castle again passed to new hands in 1974 when it was given to the County Council who are the current owners of the Castle.

Unfortunately, a devastating fire in 1977 destroyed the interior and since then an ambitious restoration programme has begun. Today, you can visit Margam Country Park to enjoy the castle, stunning gardens, walking trails, and adventure playgrounds.

15. Carmarthen Castle

Carmarthen Castle would have once dominated the medieval town of Carmarthen. It is thought that the first Castle was built in the area in 1094 however, this may have been just further down the river. After 1105 the records refer to Carmarthen by name so by this point there must have been a Norman castle on the site where the Castle stands today.

During the medieval period, as in the Roman period, Carmarthen was the administrative centre of southwest Wales. It, therefore, was under attack consistently. The Castle was taken by Llywelyn the Great in 1215 and after which William Marshal recaptured the fortress and began some renovation work on it.

Throughout the centuries that followed the Castle was added to further until in 1789 when it became the county prison3 (source: Visit Wales).

16. Laugharne Castle

Laugharne Castle held a special place in the heart of the beloved Dylan Thomas who wrote his ‘Portrait of the Artist as a Young Dog’ in the castle summerhouse. Two of the giant medieval stone towers stand guard over the remains of the Tudor mansion set within the 19th century ornamental gardens. Because of the vicious conflict between the Welsh and the English, the Castle was left in near ruin.

However, the Elizabethan courtier Sir John Perrot rescued the 13th-century fortress and renovated it into a proper residence for a gentleman. He constructed a grand hall which was complete with massive windows that look out over the river. Unfortunately for him, Sir John Perrot met a gruesome end when he was executed for high treason in 15924 (source: CADW).

Notable Mentions

Pennard Castle

Arguably the most picturesque castle in South Wales, Pennard is a ruin that sits atop a hill overlooking Three Cliffs Bay which itself is like something out of a fantasy novel. If accessed from the beach be prepared for a steep climb but the view and atmosphere from the ruins is definitely worth it.

Ogmore Castle

Ogmore Castle did not make my ‘best castles’ list because of its ruined state, however, it still provides a spectacular day out. Sat on the banks of the Ewenny River with its very own ancient stepping stones, Ogmore, like Pennard is like something out of a fantasy world.

Candleston Castle

Once a 14th-century fortified manor house, Candleston Castle is now an ivy-covered ruin. Nevertheless, its woodland surrounding and crumbling wall create a whimsical atmosphere. 

Hay Castle

Recently opened after major renovation work, Hay Castle is another Wales/England border castle. The Castle was constructed in the medieval period but what remains is the 17th-century mansion. 

Roch Castle

Roch Castle is a great option if your dream is to stay in a castle in Wales. Now a luxury hotel, this Castle dates as far back as the 12th-century.

Molly is Wales Guidebook's expert on castles. She has a master's degree in history and studied at Swansea University where she learnt about Welsh history and it's many castles. Molly loves to get out and explore historical buildings in person, with Oystermouth, Cardiff, and Caerphilly Castles among her favourites. When not geeking out on castles, Molly likes to spend her time reading, exploring the countryside or in the gym.