Neugrund is a meteorite crater in Estonia. It is 8 km (5.0 mi) in diameter and is estimated to have been formed 470 million years ago in the Ordovician period. The crater is at the bottom of the sea and is not exposed at the surface. Boulders of gneissic breccia found on the coast of Osmussaar, a nearby island, are believed to have been thrown there by the explosion.