The Gegensteine are crags near the town of Ballenstedt on the northern edge of the Harz Mountains in Germany. There are two: the Großer Gegenstein and Kleiner Gegenstein ("Great Gegenstein" and "Little Gegenstein"). They are striking, free-standing rock pinnacles and outliers of the Teufelsmauer. They lie within a nature reserve.
The Großer Gegenstein () can be ascended by means of ladders and steps carved out of the rock. A cross was erected on its summit in 1863 by order of the Prince of Anhalt; it was replaced in 1993. From the summit there are extensive views over the Harz Mountains and its northern foreland.
By the Kleiner Gegenstein () there used to be a site used for training purposes during East German times by the Gesellschaft für Sport und Technik e.g. by a driving school.