Paris (3 nights)
Canal Saint‑Martin / République, Bastille, Latin Quarter edges, Nation (transit‑friendly, walkable).
Amsterdam (2 nights)
Oost or De Pijp for value; near Centraal for convenience (often pricier). Use OVpay/contactless or the GVB app; always check in/out.
Cologne (1 night)
Near Köln Hbf / Altstadt‑Nord for the simplest bag drop + cathedral + Rhine sunset + early train.
Berlin (3 nights)
Mitte (sights), Prenzlauer Berg (calmer), Friedrichshain (Wall access), Kreuzberg (food).
The full plan includes a tighter “pick your base” decision guide and station‑to‑neighborhood navigation notes.