Idstein is a German town located in the Rheingau-Taunus-Kreis district within the Regierungsbezirk of Darmstadt in the state of Hesse. It has a population of approximately 25,000 inhabitants.
The town is notable for its well-preserved historical Altstadt (old town). Due to these architectural features, Idstein is part of the Deutsche Fachwerkstraße, a designated route connecting various towns characterized by fine timber-framed buildings and houses. Additionally, the town hosted the 42nd Hessentag state festival in 2002.