Human remains found in Peștera cu Oase ("Cave with Bones"), radiocarbon date from circa 40,000 years ago, and represent the oldest known ''Homo sapiens'' in Europe. Neolithic agriculture spread after the arrival of a mixed group of people from Thessaly in the 6th millennium BC. Excavations near a salt spring at Lunca yielded the earliest evidence for salt exploitation in Europe; here salt production began between the 5th and 4th millennium BC. The first permanent settlements developed into "proto-cities", which were larger than . The Cucuteni–Trypillia culture—the best known archaeological culture of Old Europe—flourished in Muntenia, southeastern Transylvania and northeastern Moldavia in the 3rd millennium BC.