Canterbury was a place I had on my list to see from the time I moved across. While my husband doesn't understand completely why Americans tend to be so fascinated by ancient and historical buildings, he indulges me without complaint. Although usually while mocking the American perception of 'old buildings'.
Steeped in history and tradition, Canterbury is best known for it's cathedral, which served as a popular pilgrimage site. Founded in 597 AD, it was repaired and added to through the years, and the existing structures are strikingly beautiful. There's no shortage of entertaining stories and interesting historical tidbits- the murder of Thomas Becket, while the most famous, is one of a large collection of events. I'm no history buff (Slight understatement- I'm actually totally useless at remembering dates or making any sense out of British history...), but I found the tour a really fun and engaging way to spend an afternoon. The grounds are gorgeous- some ruins and a school are housed within the compound.
After the cathedral tour, we spent a while wandering along the streets and took a punting tour along the Stour River - Krys loves being on the water so we always end up doing a boat tour if possible. It's a fun way to get a broad look at a city and if you've never tried it I would definitely encourage you to give it a go!