Need some clean air or just a time-out? Kew Gardens is a short train ride away from the city centre but is provides you with space, greenery and and a small holiday for the lungs. The garden contain tropical glasshouses and interesting architecture, so it is a treat for both body and mind.
I grew up in the countryside, and if you're ever in need some instant escape from the city, this place is like a time warp. It's a huge space full of over grown mausoleums and graves, feels like a movie set. They also do tours.
Great comic shop that stocks small press, and everything else you'd expect to find. The kids section starts at early ages and has something all the way up.