 The Laacher See volcano erupted at approximately the same time as the beginning of the Younger Dryas, and has historically been suggested as a possible cause.Laacher See is a maar lake, a lake within a broad low-relief volcanic crater about 2 km (1.2 mi) diameter.It is in Rhineland-Palatinate, Germany, about 24 km (15 mi) northwest of Koblenz and 37 km (23 mi) south of Bonn.