Currently, Mono Lake is in a geologically active area at the north end of the Mono-Inyo Craters volcanic chain and is close to Long Valley Caldera. Volcanic activity continues in the Mono Lake vicinity: the most recent eruption occurred 350 years ago, resulting in the formation of Paoha Island. Panum Crater (on the south shore of the lake) is an example of a combined rhyolite dome and cinder cone.