End your day by checking out at least one museum and in the evening take in a concert you're in Prague, after all, and should get some culture in somewhere. The
Rudolfinum is a Neo-Renaissance building built in the second half of the 19th century. It's home to the
Czech Philharmonic Orchestra and the best place to see a concert in Prague. It's also an
art gallery which hosts temporary contemporary art exhibits, and the gallery itself is something to see.
If contemporary art is your thing head out to the Dox Centre for Contemporary Art in Prague 7.
If you prefer photography hit Leica Gallery or 19th-20th century "stuff" can be found in the Decorative Arts Museum, which also has an excellent gift shop.
The Museum of Communism is surprisingly well done and the objects on display include household items and Communist-era posters. Note its entrance next to a McDonald's. Hmmm.
If you are a true music freak; hit the Dvořák Museum, which is housed in a former Baroque summer palace, or for a broader overview visit the Czech Museum of Music, another place to take in some beautiful architecture. Here you'll get a bit of calm as it can be found in a 17th-century villa; the place where Mozart wrote his famed opera Don Giovanni.
And finally, Prague and Franz Kafka seem to go hand in hand, so get a true sense of the man and his city with a visit to the Kafka Museum.