The Rennsteig (German pronunciation: [ˈʁɛnʃtaɪk]) is a ridge walk as well as a historical boundary path in the Thuringian Forest, Thuringian Highland and Franconian Forest in Central Germany. The long-distance trail runs for about 170 km (110 miles) from Eisenach and the Werra valley in the northwest to Blankenstein and the Selbitz river in the southeast.
The Rennsteig is also the watershed between the river systems of the Weser, Elbe and Rhine. The catchment areas of all three river systems meet at the Dreistromstein ("Three Rivers Rock") near Siegmundsburg.