Monte San Giorgio is a mountain and UNESCO World Heritage Site on the border between Switzerland and Italy. It is part of the Lugano Prealps, overlooking Lake Lugano in the Swiss Canton of Ticino. Monte San Giorgio is a wooded mountain, rising to 1,097 m (3,600 feet) above sea level. It has a roughly pyramidal shape, with a steep north edge sloping towards Lake Lugano and a more shallow South Slope extending towards the Po Plain. The eastern (Swiss) side of the mountain, between the municipalities of Brusino Arsizio, Riva San Vitale, and Meride, was listed as a World Heritage Site in 2003. This was in recognition of its cultural, biological, and especially paleontological significance. The site is renowned for its fossil content, one of the best known records of marine life in the Middle Triassic period. The Italian region west of Poncione d'Arzo (Porto Ceresio) was added as an extension to the World Heritage Site in 2010. History and cultural heritage Humans have inhabited Monte San Giorgio at least since the area's equivalent of the Neolithic Period, around 6,000 years ago. The south side of the mountain is home to Tremona-Castello Archaeological Park, a fortress and settlement which was continuously inhabited by artisans from the Neolithic up until the 14th century. Artifacts, architecture, and other evidence of Roman and medieval activity are abundant on and around the mountain. Productive limestone quarries were active during this period and beyond in Italy (Viggiù and Saltrio) and Switzerland (Arzo). Fossil and oil exploitation The mountain's fossil fuel deposits were exploited more recently. Motivated by a search for furnace and lamp oil for Milan, mining projects attempted to establish themselves in the late 18th and early 19th centuries, focusing on the bituminous shale of the Grenzbitumenzone (Besano Formation). Though these early efforts did not last very long, exploitation of the Grenzbitumenzone ramped up in the early 20th century once its pharmaceutical properties were discovered. In 1908, the Spinirolo plant was built for the purpose of processing the shale into saurol, an ichthyol-like skin ointment. Saurol production and mining continued until the 1950s, and operations went bankrupt in 1960. Minerals such as barite, fluorite, and galena were also prospected on the mountain during the 20th century. Italian paleontologist Giulio Curioni first mentioned that fossils were present on the mountain in 1847. The first paper focusing on Monte San Giorgio fossils in particular was published