ABSTRACTSeveral caves formed within gigantic boulders have been researched in Sweden. Many facts suggest a neotectonic origin for these bouldercaves, meaning that they were formed by earthquakes during the melting of the Weichsel-glaciation about 10.000 years B.P., when the isostatic uplift of the region could have reached 0.2–0.5 m per year.The author proposes a three-fold classification of such caves, into 1. Caves in split roches moutonnées, 2. Caves in collapsed mountain-slopes, and 3. Caves in sub-horizontally displaced mountain-tops.The most prominent evidence of neotectonic origin regarding these caves is that (a) the boulders forming many of these caves are striated, which proves that they were formed after the advance of the inland ice; (b) huge talus blocks forming caves of type 2 are situated in a manner which that indicates a momentary collapse of the mountain-slope; and (c) scarcely any weathering products are found on the floors of the caves; this indicates a recent date for cave formation.