Sinsheim is a small town in the Kraichgau hills between Heidelberg and Heilbronn, visited almost exclusively for one thing: the Technik Museum. The collection of cars, motorcycles, and military vehicles is vast, but what makes it unmissable are the two full-sized aircraft mounted on the roof — a Concorde and a Tupolev Tu-144, the only place in the world where you can walk through both supersonic airliners side by side.
The museum sprawls across several hangars and includes Formula 1 cars, vintage aircraft, locomotives, and a submarine. It is an enthusiast's paradise and easily worth half a day.
The town itself is unremarkable, but the surrounding Kraichgau is pleasant wine and cycling country, with Steinsberg Castle — the pentagonal "compass of the Kraichgau" — visible for miles. Football fans can catch a Bundesliga match at the nearby PreZero Arena, home of TSG Hoffenheim. Heidelberg is just half an hour away by train.