The key numbers and details about Caernarfon Castle in one place — build dates, cost, sieges, and royal history.
| Built | 1283 – c.1330 (47 years) |
| Commissioned by | Edward I of England |
| Architect | Master James of St George |
| Construction cost | Roughly £25,000 |
| Location | Castle Ditch, Caernarfon, Gwynedd, Wales |
| UNESCO status | World Heritage Site since 1986 |
| UNESCO group | Castles and Town Walls of King Edward in Gwynedd |
| Famous birth | Edward II, 25 April 1284 |
| Investitures held | 1911 (Edward, later Edward VIII) and 1969 (Charles III) |
| Sieges survived | 1294–95, 1403–04, English Civil War (1640s) |
| Tallest tower | Eagle Tower |
| Managed by | Cadw, the Welsh Government's heritage service |
Unlike most medieval castles, Caernarfon has no single keep — defensive strength comes from independent, polygonal towers.
The main gate was designed with six portcullises and two drawbridges, though it was never fully completed as planned.
The Eagle Tower's three turrets were each topped with a carved stone eagle, a symbol borrowed from imperial Rome.
Building work wound down around 1330 with much of the planned interior, including a grand hall, never completed.
The castle, Caernarfon's town walls, and a quay were all built as one connected defensive and administrative project.
For the full story behind these numbers, see the history of Caernarfon Castle or the architecture and layout breakdown. Ready to see it in person? Compare Caernarfon Castle tours and tickets.
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