Heidelberg German pronunciation: [ˈhaɪdəlbɛʁk] ( listen) is a city in south-west Germany. The fifth-largest city in the State of Baden-Württemberg after Stuttgart, Mannheim, Karlsruhe and Freiburg im Breisgau, Heidelberg is part of the densely populated Rhine-Neckar Metropolitan Region. In 2009, over 145,000 people lived in the city. Heidelberg lies on the River Neckar in a steep valley in the Odenwald.

A former residence of the Electoral Palatinate, Heidelberg is the location of the University of Heidelberg, well-known far beyond its and Germany's borders. Heidelberg is a popular tourist destination due to its romantic and picturesque cityscape, including Heidelberg Castle and the baroque style Old Town.