Collinas is a comune (municipality) with a population of 857 (December 31, 2015) in the province of Sud Sardegna in Sardinia. The village is located about 22 kilometers north-northeast of Villacidro and about ten kilometers northwest of Sanluri and immediately adjacent to the province of Oristano. Until 1863 the town was still called Forru. The giant graves of Sedda sa Caudeba A + B are only a few meters apart, at Collinas.