Tate Modern
I took the District line, which had really cool, old-school subway cars with wooden floors, over to Mansion House, and found my way across the Millenium Bridge to check out the Tate Modern, a huge building, that has modern art galleries on two of its six floors. In between galleries, I stopped at a cafe, overlooking the Thames, for tea. The Tate was a darned good time, and next to the Globe Theatre, which looked a little too busy for me to bother with.