海登海姆
The origin of the town's name is uncertain. Matthäus Merian (1593–1650) presumed the name to originate from its location at the Kocher river, where "frequently eels are caught", while "Aal" is German for "eel". Other explanations point to Aalen as the garrison of an ala during the Roman empire, respectively to an abridgement of the Roman name "Aquileia" as a potential name of the Roman fort, a name that nearby Heidenheim an der Brenz bore as well. Another interpretation points to a Celtic word aa meaning "water".