Montalcino is at the top of a hill 570 meters (1870 feet) above sea level and around 45 km (28 miles) from Siena. Bordered by the valleys created by the Orcia, Asso, and Ombrone rivers, it is one of the largest municipalities in Italy, and has an almost circular shape with a diameter of 16 km (10 miles) and an area of 243 km2 (94 square miles). Located 100 km (62 miles) west of the Apennines and 45 km (28 miles) to the east of the Tyrrhenian Sea, it is protected to the south by the peak of Mount Amiata. Montalcino’s hill, formed in different geological eras, has extremely variable soil characteristics both in constitution and structure. There are fairly loose soils at lower elevations, with a rather deep active layer that originated in the Quaternary period from the transport of waste. Uphill, the soil is formed by the decomposition of rocks (galestro and alberese) and has a smaller active layer.