Monte San Giorgio, a UNESCO World Heritage site in Italy and Switzerland, recognized in 2003 and extended in 2010, is a pyramid-shaped mountain renowned for its Triassic fossil deposits, dating back 245-230 million years. Its well-preserved marine reptiles, fish, and plants, unearthed from ancient lagoon beds, offer a global benchmark for paleontology. This transnational site reflects the region’s geological heritage, showcasing a prehistoric underwater world frozen in time across borders.