Where the facts come from
Every factual claim on this site links to its source. This is the full list.
How we checked
Each fact was written alongside its source. Our build script stores the source text and, for every fact, checks that the key words and figures really appear in it. 123 of 123 checks passed when this site was last built (checked 31 Oct 2026). Where we couldn’t read a source, we left the claim out. We quote short phrases only, and never reproduce Cadw’s photographs or plans.
Figures that change
Opening times, entry and visitor notices can change. Facts like these are marked “checked 31 Oct 2026”.
What we leave out
This is a site about the history of castles in Wales and about spotting and visiting them. It isn’t a visitor guide with live opening times or access advice: check with the site you’re visiting. Where one organisation’s own pages disagree with each other, or with its booklet, we show both rather than choose silently.
Cadw (22)
- Cadw: Castles of the Lords and Princes of Wales (5 facts)
- Cadw: The Castles and Town Walls of King Edward (6 facts)
- Cadw booklet: The Castles of the Lords and Princes of Wales (PDF) (29 facts)
- Cadw: Castell Caernarfon (4 facts)
- Cadw: More about Castell Caernarfon (3 facts)
- Cadw: Castell Conwy (4 facts)
- Cadw: More about Castell Conwy (3 facts)
- Cadw: Castell Harlech (2 facts)
- Cadw: More about Castell Harlech (4 facts)
- Cadw: Beaumaris Castle (5 facts)
- Cadw: More about Beaumaris Castle (4 facts)
- Cadw: Castell Rhuddlan (4 facts)
- Cadw: More about Castell Rhuddlan (4 facts)
- Cadw: Castell Dolwyddelan (5 facts)
- Cadw: More about Castell Dolwyddelan (8 facts)
- Cadw: Castell Cricieth (4 facts)
- Cadw: More about Castell Cricieth (2 facts)
- Cadw: Castell y Bere (2 facts)
- Cadw: More about Castell y Bere (4 facts)
- Cadw: Castell Dolbadarn (4 facts)
- Cadw: Caerphilly Castle (4 facts)
- Cadw: More about Caerphilly Castle (1 fact)
UNESCO World Heritage Centre (1)
GOV.UK (Department for Education) (1)
When sources disagree
Where sources give different figures, we show all of them, with links, and say how we handle it.
How many castles did the Welsh build?
- With the remains of up to 500 earthwork and stone castles, Cadw calls Wales truly “a land of castles”. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
- Fewer than 30 surviving castles in Wales are formally recorded as Welsh foundations, though the original number must have been much higher. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
- Cadw’s Dolwyddelan page says that out of more than 470 fortresses in Wales, fewer than 40 were definitely built by native hands. Cadw: More about Castell Dolwyddelan
How we handle it: Cadw’s booklet counts up to 500 earthwork and stone castles in Wales, with fewer than 30 surviving castles formally recorded as Welsh foundations; Cadw’s Dolwyddelan page says more than 470 fortresses, fewer than 40 definitely built by native hands. We quote each figure with its own source and do not merge them.
When was Dolbadarn built?
- Cadw’s Dolbadarn page says it was most likely built by Llywelyn the Great in the late 12th or early 13th century. Cadw: Castell Dolbadarn
- Cadw’s booklet says it was probably built in the last decades before his death in 1240. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
How we handle it: Cadw’s Dolbadarn page says late 12th or early 13th century; its booklet says the last decades before 1240. Both say Llywelyn the Great probably built it. We give both.
When was Dolwyddelan built?
- Cadw says Llywelyn began Dolwyddelan some time after 1210. Cadw: More about Castell Dolwyddelan
- Cadw’s booklet says probably between 1210 and his death in 1240, replacing an earlier castle, Tomen Castell. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
How we handle it: One Cadw page says some time after 1210; the booklet says probably between 1210 and 1240. These fit together; we say “after 1210” and show both.
When did building stop at Edward’s castles?
- UNESCO says building went on until 1330 at Caernarfon and 1331 at Beaumaris. UNESCO World Heritage Centre: Castles and Town Walls of King Edward in Gwynedd
- Cadw says all four were begun and substantially completed between 1283 and 1330. Cadw: The Castles and Town Walls of King Edward
- Cadw’s Beaumaris page says building had petered out by the 1320s. Cadw: Beaumaris Castle
How we handle it: UNESCO says building went on until 1330 at Caernarfon and 1331 at Beaumaris; Cadw says all four castles were begun and substantially completed between 1283 and 1330, and that work at Beaumaris petered out by the 1320s, leaving it unfinished. We show all three.
Castell y Bere: who built it, and when did the English leave?
- Castell y Bere was begun by Llywelyn the Great in 1221 and stayed in use until 1294. Cadw: Castell y Bere
- Cadw’s booklet notes that some parts of Castell y Bere may have been built by his grandson, Llywelyn ap Gruffudd. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
- The booklet says the English seem to have abandoned Castell y Bere by the end of the 13th century; Cadw’s history page says they left during an uprising in 1294. Cadw: More about Castell y Bere
How we handle it: Cadw says Llywelyn the Great began it in 1221; the booklet adds that some parts may be his grandson’s work. The booklet and Cadw’s history page describe the English departure differently. We give both.
Criccieth: begun when, and attacked when?
- Criccieth’s great gatehouse, with D-shaped towers, was built by Llywelyn the Great; his grandson added the outer ward. Cadw: Castell Cricieth
- Cadw’s booklet says Criccieth was begun by Llywelyn ap Iorwerth in the 1230s. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
- In 1404 Owain Glyndŵr’s forces burnt the towers red. Cadw: Castell Cricieth
- The booklet says Glyndŵr’s forces besieged Criccieth in 1403 and it was later destroyed. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
How we handle it: Cadw’s Criccieth page says Owain Glyndŵr’s forces burnt the towers in 1404; the booklet says they besieged it in 1403. The booklet dates the start to the 1230s. We give each year with its source.