Well worth a visit, I visited in July and it was really hot and full of germans.

It is worth using the tram system as the metro is a real rip off and also go exploring, we went to the second castle in Prague, a real haven for peace after the first castle. And take the number 12 tram to the end of the line, it leads to a wonderful park with an open air swimming pool and lots of public access paths thro fields and gorges.

Lots of history too, just avoid the drunken Brits on stag and hen nights.