Berlin

Berlin runs on transit at every hour, which suits a city whose nights start late. The FEX airport express reaches Hauptbahnhof from BER in 23 minutes, and the U-Bahn and S-Bahn keep running through the night on weekends, with night buses covering the gaps. The ABC ticket that covers the airport also covers Potsdam, so the palaces and gardens of Sanssouci are a cheap regional-train ride from the center. The lakes of the Grunewald and the Wannsee beach are S-Bahn trips, and the Deutschlandticket stretches further, to the canals and forests of the Spreewald by regional train. Berlin is spread out, so expect to ride rather than walk between neighborhoods.