The Steinbach is a right and northeastern tributary of the Main near Kleinostheim in the Bavarian Spessart .

It flows into the narrow Steinbach valley, where the Menzenmühle is believed to have been located.

A few hundred meters further on, on a rock face by the stream, the so-called 'Jahnfelsen', a plaque honors the gymnastics father Jahn.

This igneous rock filled a volcanic vent that was formed around 43 million years ago.

In Kleinostheim, the Steinbach is now completely piped and flows into the Main not far from the truck tank depot.