After that we took the tube to Bank, walked past the Monument (where else in the world would have the audacity to call something "The Monument"?) and over London Bridge to find our way to Tate Modern. We didn't have too long so we walked around the Flux exhibit which saw everything from Cubism to Lichtenstein via Bridget Riley. Very cool.
We ended the day with dinner at a Greek restaurant on the south bank, a walk over the 'wobbly' Millennium Bridge and across London in the failing light.