The Botanical Garden in Cambridge is a pleasant place to wander around. It's not as grand as Kew but I think it has more charm. I may be biased as I've been coming here since I was little.
 There are some very well tended beds and handsome specimens of plants from around the world. Besides that I like the way they have given over several of the grassy areas to naturalistic meadow style plantings. I was interested to see the simple combination of various narcissus species with Chionodoxa forbessi (sometimes called Glory of the Snow).
 I have planted the same pairing here in London and it's very pretty, though I have to admit the effect is not quite so expansive in a back garden!