Discover the best medieval castles in Wales, including the famous “Iron Ring” of castles built by King Edward I of England to secure his conquest of Gwynedd in North Wales. Wales is home to one of the highest concentrations of castles in the world, earning its reputation as a land of mighty and historic fortresses. The strength and strategic design of North Wales’ castles stand as a lasting legacy of King Edward I’s military campaigns and architectural innovation.

In order to secure the control of Wales, King Edward I formed what is known as the “Iron Ring” and circles Gwynedd, North Wales with formidable castles. This was a strategy that King Edward adapted in order to crush and intimidate the Welsh population. There are more than 600 Welsh Castles
This strategy apparently started in 1278 following the Welsh rebellion. Initially, King Edward I commissioned the first four major castles in Wales and they were Flint, Rhuddlan, Builth, and Aberystwyth. After the second rebellion, more buildings and castles were built including Caernarfon, Conwy, Harlech, and Beaumaris castles.
It was through these Welsh castles that King Edward I was able to keep his reign. These massive and strong power bases brought by these Medieval Welsh Castles as well as his purpose-built township helped him keep his reign furthermore.
To this day, these castles have been renowned all over the world. Some of these castles have been protected by UNESCO as part of World Heritage.
Abergavenny Castle Ruins *South Wales
Abergavenny was one of the earliest castles in Wales, Abergavenny which can be dated back to 1087. It originally had a motte and bailey structure and the first tower built on top of the motte was made of wood. During the turbulent times throughout the 12th century, the castle had been handed back and forth between the English and the Welsh.
It was also said to have been significantly strengthened during the 13th and 14th centuries while it was under the administration of the Hastings family. However, most of the buildings were badly damaged during the English Civil War and the castle was slighted to prevent it from becoming used as a stronghold again.
Caerphilly Castle *South Wales
Caerphilly Castle is located in the town of Caerphilly. It is the largest castle in Wales and the second largest in Britain. This 13th-century stone structure and fortress was built by the 7th Earl of Gloucester Gilbert de Clare.
The construction of the castle was to take advantage of the extensive water defense that the lakes to the north and south offered.
Kidwelly Castle *South Wales
Kidwelly Castle was built north of Llanelli in 1106 by the Bishop of Salisbury since he served as the Justiciar of England. It was built primarily to defend the roads to the west of Wales. The half-moon shape of the castle defends one side of the river and is a common Norman style of building fortresses.
However, the castle had several additions such as a rectangular stronghold with round towers, a kitchen, a garrison, and a chapel.
Caernarfon Castle *North Wales
Caernarfon Castle was constructed under the order of King Edward I. It was situated on the northwest side of Wales. This was where King Edward’s son was born and where he was later on crowned as the first English Prince of Wales.
The castle showcased King Edward’s Constantinople concentric influences such as the famous dream story where a King wanted a castle to be built in a beautiful place. Although it was designed as a military castle, this was where King Edward’s grand ideas of a castle were born.
To this day, the Caernarfon castle has been restored impressively attracting over 200 million visitors every year.
Harlech Castle *North Wales
Harlech Castle can be found in the south of Porthmadog. This also forms part of King Edward’s chain of castles called the Iron Ring. It was built by Master James of St. George, a military architectural genius.
The Harlech castle took advantage of its high position and its natural surroundings to defend inhabitants from attacks from the land or sea.
Men of Harlech refers to the unofficial Welsh anthem that honors the longest siege in British history, where the King’s forces defended the Harlech castle during ‘The Wars of the Roses
Conwy Castle *North Wales
Conwy Castle probably was the only one that did not have concentric walls within walls. This was because Cowny, the town where it was situated was already walled ad had over three-quarters of a mile of guarded towers.
The castle appeared to have grown naturally out of a rock with huge curtain walls and eight round towers. This structure has provided the town with quite an awesome and significant presence.
18 Wonderful Medieval Castles in Wales to Visit
1. Beaumaris Castle
- Dated 1295
- Built by James of St George for King Edward I
- Concentric Castle
- Fortress of Immense Size and Near Perfect Symmetry
- Four Concentric Rings
- Water-filled Moat
- 300 Arrow Loops to Outer Walls
- Location – Island of Anglesey North Wales
See Beaumaris Castle Official Website
2. Bodelwyddan Castle
- Dated 1460
- Bulit by the Humphreys family of Anglesey as a Manor House
- Location Bodelwyddan, near Rhyl, Denbighshire in Wales
See Bodelwyddan Castle Official Website
3. Caerphilly Castle
- Built by Gilbert de Clare
- Second Largest Castle in Britain
- First Concentric Castle in Britain
- Huge Gatehouse
- Network of Moats and Dams
- Circular Towers
- Location – Caerphilly in South Wales
See Caerphilly Castle Official Website
4. Caernarfon Castle
- Built by Edward I’s Architect Master James of St George
- Imposing Grand Castle
- Took 47 Years to Build at a Total Cost of £25,000
- Immense Curtain Walls
- Polygonal Towers
- Eagle Statues
- Legendary Castle Like no Other
- Location Caernarfon (Royal Town)
- On the banks of the River Seiont
See Caernarfon Castle Official Website
5. Caldicot Castle
- Built By the Normans
- Norman Period 11 – 12th Century
- Well preserved Battlements
- Castle Dungeon
- Haunted Castle
- Tower with Views of Severn Estuary
- Close to River Nedern
- Location Caldicot Town
See Caldicot Castle Official Website
6. Carmarthen Castle
- Carmarthen Castle Views over the River Twyi
- Norman Castle
- Built by Norman William fitz Baldwin
- Dated 12th Century
- Massive Stone Defences
- Dungeon
- Great Tower
- Gatehouse
- Hall, Kitchen, Chapel
- Portcullis *Murder Holes
- Location Carmarthen South Wales
See Carmarthen Castle Official Website
7. Castell Coch ‘Red Castle’
- Fairy Tale Castle
- Dated 11th Century
- Great Towers *Conical Roofs
- Built by Architect William Burge for Marquess of Bute
- Voted Best Castle in Wales on Numerous Occasions
See Castell Castle Official Website
8. Chepstow Castle
- Dated 1067
- Norman Castle
- Built by Earl William fitz Osbern (Friend of William the Conqueror)
- Wonderfully Preserved Castle
- Great Views of the River Wye
- Famous Owners William Marshal (Earl of Pembroke), Roger Bigod (Earl of Norfolk) and Charles Somerset (Earl of Worcester)
- Great Towers and Gatehouse
- Good Example of a Medieval Castles Defences
- Location Chepstow South Wales
See Chepstow Castle Official Website
9. Chirk Castle
- Built in 1295 (Plantagenet Period)
- Built by Roger Mortimer de Chirk
- Built for King Edward I
- One of King Edward I Famous Ring of Fortresses in North Wales
- The Castle sold for £5000 in 1593
- Notable Feature *Wonderful Gardens
- Surrounding Parkland Deer Park
See Chirk Castle Official Website
10. Criccieth Castle
- Amazing views astonishing views over the sweep of Cardigan Bay
- Painted By Turner
- Built by Llywelyn ap Iorwerth (Llywelyn the Great)
- Gatehouse flanked by D-shaped Stone Towers
- Conquered by English King Edward I who added Catapult Defenses
- Remained under English Control until 1404 when it was captured by Owain Glyndŵr
See Criccieth Castle Official Website
11. Conwy Castle
- Walk around the Castles Battlements *Best in Britain
- Magnificent & well preserved Castle
- Great Views of Walled Medieval Conwy Town
- Built by Architect Master James of St George on Orders of King Edward I
- Date Built 1283 – 1287
- King Edward I Famous Ring of Castles Beaumaris, Harlech & Caernarfon
- Magnificent Curtain Wall & 8 Grand Towers
- Location – Conwy Town North Wales
See Conwy Castle Official Website
12. Harlech Castle
- Best Setting of all Edward I’s Castles in North Wales
- Overlooking Sea and Snowdonia Mountains
- Built by Architect Master James of St George on Orders of King Edward I
- Built 1282 – 1289
- Concentric Castle – Walls within Walls’
- Daunting Natural Defences.
See Harlech Castle Official Website
13. Kidwelly Castle
- Norman ‘Ringwork Castle’
- Romantic Castle Appearance
- Famous Appearance in ‘Monty Python and the Holy Grail’ Movie
- Stone ‘Castle within a Castle’ that still stands today created in 1280s by the Chaworth Brothers
- Imposing Gatehouse
- Drawbridge & Portcullis
- 4 Square Towers around Inner Ward
See Kidwelly Castle Official Website
14. Laugharne Castle
- Mighty Medieval Norman Castle
- Dylan Thomas, Laugharne’s Famous Resident.
- 2 Massive Stone Towers
- Magnificent Tudor Mansion
- Stunning Gardens
- Intriguing History
See Laugharne Castle Official Website
15. Pembroke Castle
- Pembroke Castle
- Location – Pembrokeshire in Wales.
- Partially Restored
- Built by Arnulf of Montgomery in 1093
- Owned by William Marshal in 12th-century Britain

See Pembroke Castle Official Website
16. Powis Castle *Castell Powys
- Powis Castle (Welsh: Castell Powys)
- Wonderful Gardens
- Magnificent Interior
- Built 13th Century
- Buit by Gruffydd ap Gwenwynwyn (Welsh Prince)
- Rare English Baroque garden.
- Location Near Welshpool, in Powys, Wales
See Powis Castle Official Website
17. Raglan Castle
- Grandest castle ever built by the Welsh
- Fortress Appearance
- Moated Great Tower added in 1435
- Mighty Gatehouse with flared ‘machicolations’
- Intimidating & Imposing Castle
- Finest Renaissance Gardens in Britain
See Raglan Castle Official Website
18. Rhuddlan Castle
- Grand Inland Castle that Towers above the River Clwyd
- Built in 1277
- Built on Orders of Medieval King Edward I (Famous Iron Ring of Castles)
- Designed by Master Architect James of St George
- Advanced Defensive Concentric Castle with ‘Walls within Walls’
- Magnificent Diamond-Shaped Inner Stronghold
- Twin-Towered Gatehouses
- Lower Turreted Walls.
- Deep Moat
See Rhuddlan Castle Official Website
Other Welsh Castles Worth a Mention
Swansea Castle
See Swansea Castle Official Website
Penrhyn Castle
See Penrhyn Castle Official Website
Castle Ruins in Wales
The following is a list of important Castle ruins in Wales, there are not many images available of these ruins and little left remaining.
Deganwy Castle Ruins
Deganwy Castle can be found at the mouth of the River Conwy, a river north of Wales. What is now a number of ditches and mounds on top of the massive rock was formed from the remains of a fortress during the dark ages. This served as the headquarters of Maelgwn Gwynedd, King of Gwynedd from 520 to 547. Historians believed it is most likely that Deganwy was the first to occupy the castle during Roman times.
The castle was rebuilt in stone by the English King Henry III. However, it was later on abandoned and finally destroyed in 1263 by Llywelyn ap Gruffudd, Prince of Wales. The ruins seen today are remnants of King Henry’s fortification.
Caer Penrhos Ruins
Caer Penrhos castle was a very well preserved earthwork and a fortified version of the castle is believed to have been set within an earlier Iron Age earthwork serving as its bailey. It was built around the 11th century by Cadwaladr, the son of Gruffydd ap Cynan.
Ewloe Castle Ruins
Ewloe Castle was built with a D-shape which was a trademark and very typical among Welsh castles built by Llywelyn ap Gruffudd. This castle was built from local stone and is believed that its construction may not have been complete before the castle had fallen into the hands of English King, Edward I in 1277.
Flint Castle Ruins
Flint Castle was built by the English King Edward I in his campaign to conquer Wales. It was the first of Edward’s chain of fortresses that surrounded North Wales called the ‘Iron Ring’. These structures were built in 1277 and were constructed primarily to subjugate the unruly Welsh princes during that time.
Flint castle was besieged by the forces of Dafydd ap Gruffydd during the Welsh Wars and was later attacked again during the revolt of Madog ap Llywelyn in 1294. However, during the English Civil War, it was held by Royalists but was later on captured in 1647 by the Parliamentarians.
Grosmont Castle Ruins
Grosmont Castle was the first castle with earth and timber motte and bailey fortification. It was rebuilt in local red sandstone in the 13th century and was enclosed by a high wall and three stone towers. King Henry III granted this castle to his son Edmond Crouchback in 1267, who wanted to convert it into a residence. However, the Welsh army attacked the fortress in March 1405.
The English King Henry V. Grosmont appears to have fallen into disuse after this as records indicated that the castle had been abandoned.
Castles in Wales Summary
The castles built by King Edward I marked the completion and extension of King Henry III, his father’s scheme. With a very well-conceived strategic plan, he has built the fearsome Iron Ring of massive fortresses that represented Europe’s most impressive medieval structural project.
These castles were built for one reason: to subjugate the princes of Welsh and prevent the recurrence of a massive military campaign against him. Today, King Edward’s project has earned Wales the title of the Land of Castles, having the highest number of castles per square mile all over the world.
Wales lies in the western territory of the United Kingdom and has an unrivaled heritage of glorious medieval Welsh castles.