It’s just over 1½km from the car park for Nuraghe Albucciu (see this site for access, facility and ticket details) to Malchittu Temple; the path is generally wide and sandy, but does climb a bit, and the last section to reach the temple is a scramble up uneven rocks. So not recommended for the less mobile!
The temple is a very unusual structure for Sardinia and is situated between two rocky outcrops with fantastic views over the surrounding area. There’s an entrance foyer, with one straight and one curved wall, and a doorway into the main part of the temple, where niches for offerings, and a central hearth, can be seen. There’s an oak tree growing towards the back of the structure. The walls are really impressive and a scramble up the rocks on either side give great views down into the temple.
At the bottom of the rocky scramble, there’s the remains of another structure.
It’s well worth allowing a couple of hours to view this group of sites (here and Albucciu and Moru).