Losa is a tholosnuraghe of a more complex type, with an unfinished triangular bastion. It consists of the central, largely complete main tower, around which there are three smaller tower remains arranged in a triangle. There are three larger niches in the main chamber. Within the mighty walls there is a staircase to the second floor. This has not been preserved. The main tower is characterized by a regular surface. The rectangular cuboids used become smaller towards the top; only a few “filler stones” were used. To the northwest there is a wall with two further towers that encloses a kind of courtyard. These small towers are made of polyhedral cuboids; their surface appears chaotic compared to the main tower. Directly opposite the main entrance to the nuraghe is another round building with 2 entrances and wall niches.