The Tumulus of St. Michel is a megalithic grave mound, located east of Carnac. The 125m long, 60m wide and 10m high mound is the largest grave mound in continental Europe. The age of the monument, and the chronology of the construction of the central burial-chambers and outlying dolmen have been the subject of much speculation. Ancient samples were radiocarbon dated, but the results were too disparate to be significant. Recent excavations point to this large tumulus being constructed in several stages but in a rather short lapse of time, around the middle of the 5th millennium B.C. Today there is a chapel built on top of it.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.