A treasure trove in the The City of London. The Archive of London. Strongrooms hold kilometres of shelving; boxes of matter that has somehow been catalogued and categorised in a traceable manner by the public, for academic, genealogical and other research. This beautiful book is from a box on Epping Forest. On the same visit, I looked through photographs of Blitz singsongs in Bethnal Green Underground station, 1980s anti-Thatcher / pro-GLC gig posters and paper concertina optical models of the Crystal Palace.
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.
I grew up in Brighton which is full of cheesy bars like this. If you can handle being surrounded by multiple screens playing Kylie at full volume, its pretty much the cheapest bar in central london. The cliental is so varied its great for people watching and completely un pretentious.