Schloss Fürstenau stands just north of Michelstadt's station in Steinbach, close to Einhard's Basilica. The complex grew from an older moated castle into a palace of the Counts of Erbach-Fürstenau, with layers of stone, timber, towers, and courtyards.
It is best treated as part of a Steinbach walk rather than a standalone destination. Pair it with the basilica and you get a compact lesson in how deep Michelstadt's history runs beyond the pretty old town.