Camelot

Camelot is a legendary castle/citadel associated with King Arthur, becoming the capital of his kingdom. The castle was first mentioned by Chrétien de Troyes, though in his works, Caerleon, a village in Wales and the site of the Roman city Issa Augusta, was Arthur's capital. Eventually, during the 13th century, Camelot began to supersede Caerleon in importance and earlier descriptions of Caerleon were ascribed to Camelot.

the castle was destroyed by King Mark of Cornwall after Arthur's death at Camlann.

Location
Thomas Malory, writing in the 15th century, associates the site of Camelot with Winchester, the Roman city of Venta Belgae, the "capital" of the Kingdom of Wessex. Ernst Brugger suggests Camelot was a corruption of Camlann, the site of Arthur's last battle. Roger Sherman Loomis associated it with Avalon. It has also been associated with Colchester, the Roman city of Camulodunum. However, given Chrétien de Troyes' tendency to fancifully embellish stories with invented characters, the name may be made-up.