Krakow
The old town is compact enough to cross twice in an afternoon. We start at the Barbican, follow the royal route to Wawel Hill, then drop into Kazimierz for the second half of the day.
Evening is the better slot for the Main Market Square: the cloth hall empties out and St Mary's Basilica keeps its doors open late. Bring thin-soled shoes. The cobbles here are unforgiving.