On the road to Cartajima from Parauta, just at the side of the road, is a circular pit about four metres diameter and about the same depth although it is hard to tell how deep it could have been due to rockfall etc.
As you can see from the photos, it is built into the rockside with no apparent entrance. Around the top are holes suitable for posts - perhaps for a roof?
I have an idea of its potential use but would be interested in other opinions before expressing my own.
Have a look please and let me know what you think.