One of the best places in the world to see left field, experimental and creative new music which sits outside the realm of the mainstream. It should be cherished.
I wish i went more often...Some highlights of mine include Midori Takada and Acid Mothers Temple.
A great walk down an old abandoned rail way from Finsbury Park to Highgate. Most of the original platforms are sill remaining so its an interesting place to explore...
The Greenwich Observatory with its green laser beam can transfigure any night sky. If you decide to cross the Thames via the foot tunnel, make sure you look out for the green ray. You can be on one side of the meridian in a minute, and cross to the other side on the next, without even realising it.