Berlin
Europe's largest city by area is one of its greenest — 30% green space, the Tiergarten and Tempelhofer Feld at the centre, the BVG tram and U-Bahn network targeting 100% green electricity by 2030, and a dense ring of lakes (Wannsee, Müggelsee) for summer swimming. Museumsinsel (UNESCO) holds the Pergamon and Neues Museum, and the Kreuzberg, Neukölln and Prenzlauer Berg neighbourhoods cluster the GreenSign-certified boutique hotels.
Highlights: Museumsinsel (UNESCO) · Brandenburg Gate & Tiergarten · Tempelhofer Feld cycling · Wannsee lake swimming