Grotta Gigante ("Giant Cave", Slovene: Briška jama), also known as Riesengrotte or as Grotta di Brisciachi, is a giant cave on the Italian side of the Trieste Carso, in the municipality of Sgonico. Its central cavern is 107 metres (351 ft) high, 65 metres (213 ft) wide and 130 metres (430 ft) long putting it in the 1995 Guinness Book of Records as the world's largest tourist cave.
The cave contains many large stalactites and stalagmites, many of exceptional beauty. A feature of the stalagmites is their "dish-pile" appearance, formed by water dropping from up to 80 m (260 ft) above and depositing calcium carbonate over a wide area.