The characteristic ritual altar, still kept in the small apse area at the back of the second temple building, is an excellent example of monumental sacred architecture that preserves the original chromatic value of the walls made from volcanic rock (fig. 1).

Fig. 1 - The megaron 2 temple where the altar-fireplace was discovered during a dig (From Congiu 2013, fig. 3, p. 1474).

It stands on a base of large, flat river rocks, above which alternating rows of different colour stone ashlars have been placed: a first curved line of basalt isodomum ashlars, a second row of soft vulcanite, a third of bubble-hole basalt with a ram’s protome in the centre, a fourth row of soft vulcanite, a fifth formed from five blocks of bubble-hole basalt in the centre with another ram's protome at the same point as the one on the previous row, and on the side, blocks of soft vulcanite (fig. 2).

Fig. 2 - The apse room where the altar-fireplace was found during a dig (From Congiu 2013, fig. 5, p. 1475).

The chromatic effect obtained for ornamental purposes is rather clear in the façade decorated by the two ram protomes in high relief, characterised by extremely sophisticated finishes and the quality of the stonework, and in the various dark basalt blocks reproducing the shelves around a Nuragic tower, in the centre of which there is a central ritual fireplace in which a fire was lit during ceremonies (fig. 3). The latter, circular in shape, is made of several wedge-shaped basalt blocks tied to the shelves by large lead staples.

Considerable effort was made while building it in the use of materials taken from the Ogliastra coastline, and a large use of decorative elements and chromatism by choosing mineral rocks of different colours.

Fig. 3 - Detail of ritual fireplace located in the rear room of the megaron 2 (From Congiu 2013, fig. 6, p. 1475).