Schloss Hohentübingen Swabian Alps Region

On its perch above Tübingen, this turreted 16th-century castle has a terrace overlooking the Neckar River, the Altstadt’s triangular rooftops and the vine-streaked hills beyond. An ornate Renaissance gate leads to the courtyard and the laboratory where Friedrich Miescher discovered DNA in 1869. Besides a clutch of museums, the finest of which is the Museum Alte Kulturen, the castle's highlights include the immense, 84,000-litre Grosse Fass wine vat – one of the world's oldest, dating to 1564 – which can only be visited on guided tours at 2pm, 3pm, 4pm and 5pm (book ahead online).