Matera. The town lies in a small canyon, which has been eroded in the course of years by a small stream, the Gravina. Known as "la Città Sotterranea" (the Subterranean City), Matera is well known for its historical center called "Sassi", consideredWorld Heritage Site byUNESCO since 1993, along with the Park of the Rupestrian Churches. Matera was declared Italian host of European Capital of Culture for 2019. Matera has gained international fame for its ancient town, the "Sassi di Matera" (meaning "stones of Matera"). The Sassi are houses dug into the calcareous rock itself, which is characteristic of Basilicata and Apulia. The ancient town grew in height on one slope of the ravine created by a river that is now a small stream. The ravine is known locally as "la Gravina". In the 1950s, the government of Italy forcefully relocated most of the population of the Sassi to areas of the developing modern city.