The Heidenmauer (Heathens' Wall) is Wiesbaden's oldest structure from Roman times and is found next to the Römertor (Roman Gateway). It was part of a Roman stronghold dating back to 364-375 A.D. built to ward off attacks from the Germanic tribes, Only fragments of the wall remain today.

 

The Römertor was built in 1902 with a covered wooden bridge. In the Römisches Freilichtmuseum (Roman Open-Air Museum) next to the Römertor, there are copies of stone tablets found in Wiesbaden from the Roman era.