Silchester (sĭlˈchĭstər) [key], village, Hampshire, S England. It is noted for the ruins of the Roman-British town Calleva Atrebatum. The outside walls (2,760 yd/2,524 m in circumference), forum, amphitheater, and entire plan of the city, including baths and several temples, were revealed through excavations beginning in the 1890s. In the 21st cent. possible evidence of a planned pre-Roman town was found beneath the ruins of Calleva Atrebatum.