Tower D is on the western side of the bastion of Su Nuraxi (15th-13th century B.C.), in a side position (figs. 1, 2).

Fig. 1 - Map of Su Nuraxi, nuraghe and village (from Lilliu 1962, Table LVI.1, page 328).

Fig. 2 - Aerial view of archaeological area (photo by Unicity S.p.A.).

The perimeter tower (fig. 3), that can be accessed from the courtyard through an architraved entrance and a corridor that is 3.88/2.90 metres long and 1.00/1.99 metres wide, that was originally formed by two chambers one over the other. The base diameter and the vault height are 4.00 x 7.73 metres. The tholos vault is no longer complete.

Fig. 3 - Detail of the courtyard where the entrance door to the chamber of tower D can be seen in the centre. (photo by Unicity S.p.A.).

The double row of embrasures (nine on the lower level and eight on the upper level) made in the wall of the lower chamber, can still be seen, as they were not hidden inside, but only on the outside. In the space between the entrances to towers D and E, there is an entrance (1.67 metres high) at 3.65 metres from the ground leading into a small subsidiary tholos chamber (4.23 metres diameter by 5.20 metres height), with a niche and jamb in the wall, that can be reached from the courtyard using a mobile ladder.