London, UK
Today GSE took us to St. Paul's Cathedral. My first let down was that we weren't allowed to take pictures (though at one point our tour guide said she wouldn't notice if we took a picture or two while in the stair tower). Nevertheless, we had a really detailed tour and it was actually quite amazing.
It was just so big. Standing at the west entrance and looking east it was just breath-taking. There were all these archways and domes and columns. Everything ...