Surrounded by forest, Germany’s oldest and most famous university town is renowned for its baroque Altstadt, beautiful riverside setting and evocative half-ruined hilltop castle, which draw 11.9 million visitors a year. They follow in the footsteps of the late 18th- and early 19th-century romantics, most notably the poet Goethe and Britain’s William Turner, who was inspired by Heidelberg to paint some of his greatest landscapes.