Oystermouth Castle

The Mumbles, United Kingdom

The first Oystermouth castle was founded by William de Londres of Ogmore Castle soon after 1106 following the capture of Gower by the Normans. In 1116 the Welsh of Deheubarth retook the Gower Peninsula and forced William to flee his castle which was put to the torch. The castle was rebuilt soon afterwards, but was probably destroyed again in 1137 when Gower was once more retaken by the princes of Deheubarth. The Londres or London family finally died out in 1215 when Gower was again taken by the Welsh under the leadership of Llywelyn the Great. In 1220 the Welsh were expelled from the peninsula and the government of Henry III of England returned the barony of Gower to John de Braose who rebuilt both Swansea Castle and Oystermouth.

In the 13th century the Braose family were Lords of Gower and held the castle as part of their extensive land holdings and titles, including other castles on Gower and in the Welsh Marches. The de Braose dynasty could afford to rebuild Oystermouth castle in stone. A high curtain wall was built, internal buildings added, a chapel, basements, three storey residential buildings with fireplaces and garderobes on each floor. The castle had every residential feature necessary for living in some comfort and was also refortified cleverly. Towards the end of the century Oystermouth rather than Swansea Castle became their principal residence.

By 1331 the Lords of Gower were living elsewhere and the castle declined in importance in the 14th century.

The daughter of the last de Breos Lord, Aline de Breos, who improved the chapel making it one of the finest in any castle in south Wales, later married John de Mowbray, and the Lordship of Gower including the castle at Oystermouth passed to the de Mowbrays through this marriage, and then to the Herbert family, and finally the Somersets, who became successive Marquis of Worcester and finally Dukes of Beaufort.

Decline and decay

After the Middle Ages, the castle gradually fell into ruin. It was portrayed in art in the 18th century as a picturesque ruin, and was restored by George Grant Francis in the 1840s while the castle was owned by the then Duke of Beaufort.

In 1927 the Duke of Beaufort gave the castle to Swansea Corporation; today, the castle is maintained under the responsibility of the City and County of Swansea council.

Following the first phase of conservation works Oystermouth Castle reopened to the public in 2011. The scheme includes new visitor facilities, an educational space, improvements to access and a 30-foot high glass viewing platform and bridge that leads to Alina's Chapel.


On either side of the entrance gate the walls curve inward, showing that at one time there were supposed to be two round towers built into the gatehouse. It is unknown whether these were ever built.

The chapel (on the second floor of the chapel block) has 14th century traceried windows. According to local tradition the chapel was built under the direction of Aline de Mowbray.

Remnants of an ornate medieval painting dating back to the 14th century have recently been found in the chapel. The surviving painting is thought to be over 700 years old and was spotted during conservation work in the historic attraction's chapel area. Exposure to the elements has taken its toll on the painting over time but expert Cadw analysis suggests it's a double-arched canopy that contains the figures of angels. Some of the clear elements of the painting that remain include a wing with multiple feathers and circular shapes that form a head with yellow hair surrounded by a nimbus. It's thought the painting is both highly important and testimony to the original design of the chapel attributed to Alina de Breos in the early 14th century that once formed part of a larger work of art.



Your name


Founded: 1106
Category: Castles and fortifications in United Kingdom

More Information



4.5/5 (based on Google user reviews)

User Reviews

Tommy peace (2 years ago)
Excellent castle that grows on you. This castle is more than meets the eye a maze or narrow walk ways and curious rooms let's you explore an 800 year old moment and imagine the life's of Norman lords in days long gone by. Parking is not provided so I would recommend the m and s car park or the one at the bottom of town. A one hour guided tour of the castle is provided for just an extra £1:50 and will help you spin out a visit. There is also a nice little shop and a short ten min video introducing the castle.
Nicole P (2 years ago)
Beautiful grounds with washroom facilities. You can enjoy a picnic on the grass and play games on the field. Lots of benches and shaded areas. The castle and ruins are worth the visit and doesn't cost much. Great bit of history in the center of town. Gorgeous views from the towers.
Elizabeth NVelazquez (2 years ago)
Beautiful location (The Mumbles) of these castle ruins. Dog friendly...our furbaby was able to explore the castle walls, towers, Chapel and grounds. Due to parking time limits we were only able to spend 1hr walking the grounds. There is an M&S at the foot of the hill near the entrance to the grounds. Plenty of space to pick up a picnic and just enjoy the beauty.
Debora Worrall (2 years ago)
Such a lovely atmospheric castle with stunning views across the Mumbles bay. Welcomed by the most wonderful and friendly guide. There is a film show at the beginning telling you all the history of this beautiful castle. Well worth a visit.
Kinga Borycka (2 years ago)
Beautiful place! When you come in and buy the tickets there is a video played about the history of the castle which is fascinating and most of the areas in the castle are open to the public to view. Don’t make the same mistake as me and wear heels as some of the areas will be hard to get to if you do. Honestly I would really recommend this place as it is truly worth the trip.
Powered by Google

Featured Historic Landmarks, Sites & Buildings

Historic Site of the week

The Church of the Holy Cross

The church of the former Franciscan monastery was built probably between 1515 and 1520. It is located in the UNESCO World Heritage Site of Old Rauma. The church stands by the small stream of Raumanjoki (Rauma river).

The exact age of the Church of the Holy Cross is unknown, but it was built to serve as the monastery church of the Rauma Franciscan Friary. The monastery had been established in the early 15th century and a wooden church was built on this location around the year 1420.

The Church of the Holy Cross served the monastery until 1538, when it was abandoned for a hundred years as the Franciscan friary was disbanded in the Swedish Reformation. The church was re-established as a Lutheran church in 1640, when the nearby Church of the Holy Trinity was destroyed by fire.

The choir of the two-aisle grey granite church features medieval murals and frescoes. The white steeple of the church was built in 1816 and has served as a landmark for seafarers.