Wasp nest on Opuntia
No interactions present.
Has some of the nest been cut away for the camera?
All the wasp nests i have found have had an outer shell with a bit that looks like what you are showing close to where it is fixed to the structure they are in.
These are not in UK. This sort of nest is typical of the Polistes wasps, which this may well be. I will leave it to someone who knows the Med wasps to add a revision.
recording wildlife with The Recorder's Year on www.hbrg.org.uk/TRY.html.
No the nest appears to be under construction and is as found.
They do look a little different to the ones we get in the UK. They will be from a dry climate and will not need to shield the nest from the weather to such an extent.
Lat/Lng: 36.991, -4.3687