The red giant
¡When you visit this historical nuraghe, it's best to find a qualified guide to accompany you and explain a bit of the back-story. The whole site takes about an hour to see, but it's an hour that's worth it. If you want to make the most out of it, I'd also suggest visiting the sacred well of On Putzu (just follow the signs on the highway).
Or, if you'd like to explore the area on foot, try the El Putzu walking trail. It's quite an experience treading where thousands and thousands of ancient footsteps have passed before.
During springtime, the whole area is full of wildflowers blooming around the ponds that form on the basalt mesa. Again, I'd recommend having one of the local guides show you around.