Maybe an obvious choice, but the Barbican is always good. My favourite space in there is the curve gallery, last time I went was for Cory Arcangel's 'Beat the Champ'. I love the architecture, although not many people do. I think it was voted 'London's ugliest building' in 2003.
Lisson Gallery is one of the most influential and longest-running international contemporary art galleries in the world. Since being founded in 1967 by Nicholas Logsdail, it has championed the careers of artists who have transformed the way art was made and presented.
Relaxed with character. Tiny garden at the back overlooked by Waterloo train station. Not sure if mother cat still lives there. Nice to go with friends or alone. Books. Good for a coffee and cake or a bottle of beer. Spiral staircase down to basement. One loo serves the place - tip - lock the door, don't just rely on the curtain and save an awkward encounter.
Photo credit: http://www.appletoothpaste.co.uk/2017/05/coffee-scooter-caffe-london.html
The Sackler Crossing is part of a route through the 120 hectares of Kew Gardens, designed by John Pawson in 2006. Set low to the surface of the lake, it seems to float across the water.
By far the best bagels in London, they are open 24 hours and being just down the road from my flat a bit too local. It is run by a man called Mr Sammy, who doesn't muck about with portion size. It is well worth a visit especially for their smoked salmon and cream cheese speciality.