I was most impressed when visiting Battle Abbey last year. The Battle of Hastings took place in Battle on the only date known by most British children. (Clue - it's not 1492)(Also the most popular number used as an alarm code in British libraries - I'm posting that so they change it!)

The particularly good thing about the interpetation of the site was that it presented the events leading up to the battle from two points of view along two opposite sides of a series of rooms. As the site is so close to France and must have lots of visitors from France I thought it was very interesting and something I would like to see more often.