The largest Roman amphitheatre in Britain, used for entertainment and military training by the 20th Legion, based at the fortress of ‘Deva’ (Chester). Excavations by English Heritage and Chester City Council in 2004-5 revealed two successive stone-built amphitheatres with wooden seating. The first included access to the upper tiers of seats via stairs on the rear wall, as at Pompeii, and had a small shrine next to its north entrance. The second provided seat access via vaulted stairways. The two buildings differed both from each other and from all other British amphitheatres, underlining the importance of Roman Chester.