Caernarfon Castle: The 13th-century stone fortress of King Edward I

Caernarfon Castle is a medieval fortress in Gwynedd, north-west Wales. While the first fortification on the site was a motte-and-bailey castle built in the late 11th century, King Edward I of England began to replace it with the current stone structure in 1283. This grand structure acted as the administrative centre of north Wales, and as a result the defences were built on a grand scale. There was a deliberate link with Caernarfon's Roman past - nearby is the Roman fort of Segontium - and the castle's walls are reminiscent of the Walls of Constantinople.

Construction continued over the winter of 1283-84 and ended in 1330, costing between £20,000 and £25,000. While the castle appears mostly complete from the outside, the interior buildings no longer survive and many parts of the structure were never finished. Although the castle was captured by Madog ap Llywelyn during his rebellion in 1294, it was recaptured the following year.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons