The Barbican is worth visiting for it's brutalist architecture alone. The concert programming is really diverse; it's home to the BBC Syphony Orchestra, but you'll also find bands like the Dirty Projectors and the National amongst the classical and contemporary composer line up. Plenty of art, dance and theatre too, however, the Conservatory is the real gem that's not to be missed.
Epping Forest is a 2,400 hectares area of ancient woodland between Epping in the north and Wanstead in the south, straddling the border between Greater London and Essex. I tend to get off at Loughton Tube Station (Central Line), which is about 10–12min walk to the forest.
A small place to eat with great vegetarian/vegan food just off Camden High Street. This place does an amazing buffet at a great price, as well as serving reasonably priced tea and juices.