This converted power station is one of the largest modern-art galleries in the world, so give yourself ample time to take it all in. The permanent collection includes work by all the major 20th-century artists, though only a fraction is shown at any one time. There are also blockbuster touring shows and solo exhibitions of international artists. The huge onetime oil tanks of the old power station were opened up in 2012 for a season of performance art. These new spaces
are the first stage in a new extension of the gallery that is scheduled for completion in 2016. The bar on the top floor has gorgeous views overlooking the Thames and St. Paul's Cathedral.