One of the largest surviving pieces of Roman civil masonry in Britain, the Jewry Wall stands at the heart of Leicester's Roman past. Ratae Coritanorum was a significant Roman town, and this 9-metre section of Roman wall is all that remains of its public baths — a complex that would once have been one of the grandest buildings in the settlement.
The adjacent museum is free and covers Roman Leicester in some depth: mosaic floors, artefacts, and a well-designed layout that explains how the Roman street grid underlies the modern city. There's a good audiovisual display, and the museum occasionally hosts temporary exhibitions on regional archaeology.