Beaumaris Castle is a late 13th-century castle located in the town of Beaumaris on the Isle of Anglesey in Wales. It was built by Edward I as part of his conquest of Wales and was one of the largest and most sophisticated castles of its time.

The castle was designed by the famous military architect James of St. George and is a perfect example of the concentric castle design, with multiple layers of defenses, walls and towers. The castle was built with a highly advanced water system that used the power of the sea to supply freshwater to the castle.

Beaumaris Castle was also an important symbol of English domination over Wales, and it played a role in several key conflicts throughout history, including the Welsh rebellion of 1294-5 and the English Civil War.

Today, Beaumaris Castle is a UNESCO World Heritage Site and one of the most popular tourist destinations in Wales, attracting thousands of visitors each year. The castle is open to the public, and visitors can explore the castle's towers, walls, and chambers, and enjoy spectacular views of the surrounding countryside and coastline.