You may be lucky enough to have your travel to Frankfurt coincide with one of the city’s museum festivals. Museumsuferfest is held on the last weekend in August, complete with food, live music and entertainment, as well as special tours of collections that are usually closed to the public.
For shopping or simply exploring the city, the Bornheim quarter has a pleasing, Bohemian air. The medieval houses lining Berger Straße give way to trendy boutiques, restaurants and cafés where it is possible to spend an afternoon of people-watching while enjoying a cup of coffee and a pastry.
Enjoy a picnic at Grüneburgpark, the city's largest park, or take a walk by the River Main. For something a little more active, head for the Taunus Mountains for a lung-full of fresh air, some superb hiking routes and the ruins of three castles (Kronberg, Falkenstein, and Königstein) in a single tour. The mountains are easy to reach via public transport.