St. Martin's Chapel () stands at an elevation of 1,085 metres above sea level (NHN) at the upper end of the Katzensteig valley on the territory of Furtwangen just above the source of the Danube. It is also not far from the source of the River Elz and thus the main European watershed between the Rhine and the Danube. The West Way, a major hiking trail in the Black Forest runs past the chapel as does the long-distance ski trail from Schonach to Belchen.