Attractively situated at the junction of the Idar with the Nahe, with crags of melaphyre (basaltic rock) towering 125 m/410ft above it, Idar-Oberstein is one of Germany's leading centers of the trade in precious stones and the jewelry industry, with well-known gem-cutting establishments.
The Deutsche Edelsteinstrasse (marked by a stylized diamond) runs through the Hunsrück to the north of Idar-Oberstein in a circuit of 58km/36mi, taking in over a dozen places with gem-cutting establishments.
Idar extends up the Idar valley, with the 22-story Diamond and Precious Stone Exchange (Diamant-und Edelsteinbörse), in which is the fascinating Museum of Precious Stones (Edelsteinmuseum).
On the outskirts of Idar, in Tiefensteiner Strasse, can be found the Wieherschleifferei, an old gem-cutting center where visitors can see the stones being cut and polished.
Above Oberstein lies the Rock Church, built into a cave on the hillside. The porch dates from the 11th C. (enlarged in 1482). Higher up on the steep-sided crag are two ruined castles (11th and 12th C.).