Letocetum is owned by the National Trust, but under the guardianship of English Heritage.  You can wander around the ruins at your leisure, and read the information boards to learn about the site – all for free.  Not bad, is it?  It is situated on what was the main Roman road between London and the another Roman town near to present-day Shrewsbury.  The remains are mainly of the bath house, which was a central part of Roman life, and an inn.

There is a small museum next to it where you can learn more and see some of the excavated finds.  Unfortunately, I arrived too late, so I missed the museum.