On the other side of the Rügert are the constituent communities of Oberauroff and Niederauroff in the valley of the Auroffer Bach.
On the Wolfsbach, remnants of the like-named, now forsaken village can still be made out.
The estate Gassenbach in the town's south goes back to an old settlement called Gassenbach; for the last few years, it has belonged to the Domäne Mechtildshausen, an organic farming operation.
Idstein lies in the Taunus mountain range, north of Wiesbaden.
The town's landmark is the Hexenturm (Witches' Tower), a 12th-century bergfried and part of Idstein Castle.
West of town, beyond the Wörsbach valley, lies another high ridge with peaks ranging from the Hohe Kanzel (592 m or 1,942 ft) to the Roßberg (426 m or 1,398 ft) and the Rügert (402 m or 1,319 ft) to the Rosenkippel (379 m or 1,243 ft); to the south, the Galgenberg (348 m or 1,142 ft) forms another high area over to the Dasbach Heath.