Beaumaris Castle was the last castle to be built by Edward I in North Wales. Work started in 1295 and continued for 35 years, with over 3,500 workmen employed at the peak of construction. However, the castle was left unfinished when finance ran out. In part this was because the Welsh conquest was practically complete at the time of construction, and also because the immense cost of completing such a massive fortress would have drained funds needed for the new Scottish campaigns.
The large inner ward covers about 3/4 of an acre and was surrounded by six towers and the two great gatehouses. There was an intention to provide lavish suites of accommodation, and both gatehouses were planned to have grand arrangements of state rooms at their rear, similar to Harlech. The north gate, on the far side, was only raised as far as its hall level and the projected second storey was never built. Even as it now stands, with its five great window openings, it dominates the courtyard. Another block, of equal size, was planned for the south gate, but this was never to rise further than its footings.
The King's architect, Master James of St. George, brought all his experience to bear in designing Beaumaris — its defences and lines of supply are superbly planned. It was constructed according to a concentric plan — the inner ward is completely surrounded by the outer ward. The castle has a tidal dock allowing it to be supplied directly by sea and is surrounded by a water-filled moat. The defences include numerous ingeniously sited arrow slits, and the entrances are protected by murder holes from which substances such as hot oil could be poured over enemy forces. Attackers of Beaumaris Castle would have met 14 separate obstacles and four lines of fortification resulting from the 'walls within walls' design.
Small-scale work on the castle was carried out in the early 14th century. However, the outer walls were crenelated, and unlike many other castles Beaumaris did not suffer slighting during the Civil War — the castle remains very well-preserved.
The castle is wonderful to explore and is unlikely to be packed with tourists. It also offers wonderful views across the Menai Straight to the mountains of Snowdonia.