Monte San Giorgio is a wooded mountain (1,097 m above sea level) of the Lugano Prealps, overlooking Lake Lugano in Switzerland. It lies in the southern part of the canton of Ticino, between the municipalities of Brusino Arsizio, Riva San Vitale and Meride. Monte San Giorgio became a UNESCO World Heritage Sites in 2003, because it is the single best known record of marine life in the Middle Triassic period, and records important remains of life on land as well. The Italian region west of Poncione d'Arzo (Porto Ceresio) was added as an extension to the World Heritage Site in 2010.