The Roman Forum of Lahnau-Waldgirmes (German: Römisches Forum Lahnau-Waldgirmes) is a fortified Roman trading place, located at the edge of the modern village Waldgirmes, part of Lahnau on the Lahn, Hesse, Germany. The site has the oldest known stone buildings in Magna Germania. The archaeological evidence at Waldgirmes suggests the remains of one of a series of planned towns and market places founded by the Romans east of the Rhine and north of the Danube, with the aim of long-term growth into population centres. The complex was never completed. In the absence of any historical reference or local inscriptions, the original name of the site remains unknown.
