The ruined castle Burg Drachenfels, on the summit of the Dhill, was built between 1138 and 1167 by Archbishop Arnold I of Cologne and bears the same name. It was originally intended for the protection of the Cologne region from any assault from the south. Originally it consisted of a bergfried with court, chapel and living quarters for servants. The castle was slighted in 1634, during the Thirty Years' War, by the Protestant Swedes and never rebuilt. As a strategic asset it had outlived its usefulness. Erosion due to the continued quarrying undermined much of the remains and only a small part is left today.References:
Built around AD 90 to entertain the legionaries stationed at the fort of Caerleon (Isca), the impressive amphitheatre was the Roman equivalent of today’s multiplex cinema. Wooden benches provided seating for up to 6,000 spectators, who would gather to watch bloodthirsty displays featuring gladiatorial combat and exotic wild animals.
Long after the Romans left, the amphitheatre took on a new life in Arthurian legend. Geoffrey of Monmouth, the somewhat imaginative 12th-century scholar, wrote in his History of the Kings of Britain that Arthur was crowned in Caerleon and that the ruined amphitheatre was actually the remains of King Arthur’s Round Table.
Today it is the most complete Roman amphitheatre in Britain.