Su Nuraxi Nuraghe is located in Barumini. The site centers around a three-story tower built 3,500 years ago. The complex consists of circular defensive towers in the form of truncated cones built of dressed stone, with corbel-vaulted internal chambers. Extended and strengthened in the first half of the 1st millennium under Carthaginian pressure, it is the finest and most complete example of this remarkable form of prehistoric architecture. The site was declared a World Heritage site by UNESCO in 1997.