“The home of British art from 1500 to the present day” according to the web-site.
This gallery is on the west side of the Thames about one kilometre south of Big Ben.
Accessible buses are frequent. There is a ferry just outside with a ramp down. I was refused access a couple of years ago but from their website this is resolved. The ferry company is Thames Clippers. This time, in 2016, I actually walked from London Bridge past Elephant and Castle to the Vauxhall Bridge. I walked back along the river past Westminster. My power chair is fast and reliable and can easily do 25 km between charges so one sunny day roaming about as great fun. Otherwise I would probably use the buses, which are very accessible and only annoying during peak.
I entered from the southern “Manton entrance” on Atterbury Street. This is round the left down a long, wide ramp from the front.
This is a wonderful gallery, extensive and comprehensive. Entrance is free except for “special” exhibitions. The wheelchair access is also excellent.
In 2016 I wandered about on a weekday. The gallery was very quiet. There was a special exhibition juxtaposing the Pre-Raphaelites with associated photographs.