Cesky Krumlov is a lovely little town, but it's either a long bus journey from Florenc or a convoluted train-trip with 2 changes - and I think the castle's closed after October 31. Melnik's a pleasant little place - it's at the confluence of the Vltava and the Elbe, about 40 minutes by bus, again from Florenc. If you're into marionettes, the National Puppet Museum at Chrudim is worth a visit - easily reachable by train from Hlavni Nadrazi. Not much of a town, though - very poorly provided with pubs/restaurants, and not really anything much else to see at this time of year.