We went to visit the Prague Castle (began building in 870 AD), but unfortunately there was some reconstruction and we weren't able to see all of it. We did go to St. Vitus Cathedral which is on the castle grounds and is a great Gothic building. Of course I didn't take any pictures of the outside, sorry. The first two pictures below are of from the interior of the cathedral.
When we were in Prague in 2002 this was one of my favorite sculptures. I don't have any information on it, but I think it is really interesting. Brian's dad, Lester, seemed to like it too.
A view of Prague from the castle grounds. If only I had a nice SLR to really do this picture justice.
There is a John Lennon memorial wall near the castle, across from the French Embassy. People are allowed to decorate any part of it, but they leave the Lennon portrait and peace symbol as is.
John Lennon portrait
Imagine peace symbol