The old Konstanz road represents the chequered relationship between the two cities of St. Gallen and Konstanz. Traffic between the cities increased greatly during the Council of Konstanz (1414-1418). Konstanz cloth manufacturers had cloth made at a better price in St. Gallen and local businesses supplied booming Konstanz.

The route starts in St. Gallen’s monastery district, takes the busy main road to Wittenbach and gradually enters a green landscape, the chain of hills between the Bodensee and the Sittertobel (ravine). Past white Dottenwil Castle and shaggy highland cattle at Ruggisberg to Hagenwil Castle, a well-preserved moated castle with drawbridge. Amriswil first grew larger than the surrounding hamlets with the opening of the Thurtal railway line.

The hinterland belongs to individualists who enjoy recreation between fruit orchards, meadows and woodland. Apple and pear orchards dominate the landscape in «Mostindien», in Altnau an educational trail explains fruit growing in Thurgau. The views of the Bodensee are picture-perfect; the route approaches Kreuzlingen and after crossing an invisible border, reaches Konstanz, the German Bodensee metropolis.