Dating back to the Nuraghic Age (16^th-15^th century BC) these tombs were built for the community and the nearest village. In general, they consist of two basic parts: the corridor where the bodies were laid to rest and the exedra, usually semi-circular in shape, which was the space dedicated to rituals.

The two tombs (originally three) are about 45 metres apart and are named after the locality where they were found but are also referred to as 'Su Giganti' (the Giant). The first monument faces south with a north-south orientation, while Su Lilloni II is aligned NW/SE, with the exedra facing southeast.

Only this tomb still has the exedra, which must originally have been about 11 metres wide. Both buildings are in a poor condition, caused by abandonment over thousands of years and clandestine excavations.

Large blocks of local stone, including granite and schist, were used to construct the tombs, with basic workmanship.