Baroque fortifications in the Black Forest

The Baroque fortifications in the Black Forest, also called Baroque Schanzen or Black Forest lines, are historical, military earthworks, known as schanzen, that were built in the Black Forest in what is now Germany. They were built in the 17th century to defend the Margraviate of Baden from French invasion. Together with their adjoining defensive lines, the Black Forest fortifications formed a defensive system over 200 kilometres long that ran from north to south.

Source: Wikipedia