A walled secret garden, the Physic Garden is like a time capsule, founded in 1673 to allow apprentices of the Worshipful Society of Apothecaries of London to study the healing properties of plants, it is now a living museum. Tours are offered by volunteers with immense knowledge of botany and the cultural history of the garden or visitors can wander the grounds alone and spot odd and fascinating plants such as the mystical Mandrake.

Slightly biased as this is where I live, but Stoke Newington is great place to spend lazy saturday / sunday afternoons getting sloshed with friends. There are 10 + pubs within walking distance who all are great places for one reason or another. I'll pick out the White Hart for its huge beer garden...

Event space and studios with eclectic group of musicians, artsist, DJs primarily around jazz, world, folk, experimental music 

The best bacon sandwich you will ever eat. Pretty much fills you up for the whole day.

Outside of the major players (Tate, V&A, RA) this is probably the best programmed gallery in London