Mühlheim am Main is a town of roughly 28,500 inhabitants on the Main’s left bank in the Offenbach district in the Regierungsbezirk of Darmsta…Mühlheim am Main is a town of roughly 28,500 inhabitants on the Main’s left bank in the Offenbach district in the Regierungsbezirk of Darmstadt in Hesse, Germany. Its municipal area measures 20.67 km.