The Roman Villa at Chedwoth was discovered in 1864 by a gamekeeper and his dog in search of a prey. The mosaics were well preserved and have been examined for years. Recent radiocarbon testing has surprised investigators, however: It was created in the mid-400s or later. This is at least a generation or two after the Romans had officially left Britain.: https://www.independent.co.uk/news/science/archaeology/mosaic-chedworth-gloucestershire-roman-britain-national-trust-b1768780