My travel in UK

[Materfamilias]

How about St Albans? has a nice Ampitheatre there, bits of wall and gatehouse, hypocaust and mosaic and a reasonable little museum with a couple of nice mosaics, the town itself was the site of a couple of Battles during the later War of the Roses and the street layout has changed little since then.
There's also Fishbourne Roman Palace might be a bit early for you too, but worth a visit. Hope they help

Deb