The formation of a 20-m-high salt pillar in Mount Sedom, Dead Sea area, was analyzed and dated, and these results were complemented by measurement of present uplift rate because the pillar is a part of the actively rising Sedom diapir. Contrary to earlier assumptions, which stated that the salt pillar was formed by direct rainfall, the observed solutional notches and morphology of the neighboring chasm indicate that the salt pillar is due to a karstic cave that collapsed. The uppermost part of the cave still carried an underground ephemeral stream ~4000 yr ago, as indicated by six 14C dates of wood washed into the highest cave level. The sudden collapse that left the isolated salt pillar was probably triggered by a catastrophic earthquake. The measured uplift rate, 9.3 ± 3.5 mm/yr, shows that when the pillar formed, it was much closer to the base of Mount Sedom.