The natural grottos in the Matera region were adapted since the Paleolithic age as dwellings. They were inhabited in this kind of primitive form until the 1950s. At that time, because of extremely unsanitary conditions, their inhabitants were forcibly relocated to new government housing. In 1993, the sassi were declared a UNESCO World Heritage Site and the process of transformation began. Caves like this one are much they they have been for millennia, but others have been transformed into modern homes, businesses, and hotels.