Krakow - we enjoyed wandering about the beautiful main square; we stayed in the Jewish Quarter - loads of cool, quirky bars & restaurants there; we visited Shindlers Factory and the Jewish Ghetto and the Eagle Pharmacy Museum - all recommended. Great hot chocolate & cake in the E. Wedel Cafe on the main square. We did the Saltmines but it was my least favourite thing to do there.
Budapest - we did a Jewish walking tour and you can find the last remaining part of the Ghetto wall tucked down an alleyway - very moving. Coffee / cake in the fabulous New York Cafe, and also in Gerbauds Cafe, we visited the Gellert Baths and spent most of a day there - amazing, get the funicualr up to the castle and spend half a day exploring that, we did a bus tour where the bus drove into the Danube and became a boat tour!
Prague - have coffee / cake in the amazing restored Grant Orient Cubist Cafe upstairs over the House of the Black Madonna, have coffee / cake in the Imperial Cafe in the Town Hall - glorious interior, visit the castle and also visit the Alchemy Museum with the underground alchemy lab - highly recommend this, check out the Astronomical clock and we also did a WWII walking tour with a guide and we visited the underground tunnels as part of this
We brought DD on these trips so they were also interspersed with looking around shops etc!
Have not been to Vienna yet but it is on our list and we would like to see the Scessionist architecture, the horse riding school amongst other things.
LOVE all of those cities though - so much to see and do. We love history.