Sam - are you interested in craters and geology? Back home I was looking at the IGN map "In Azaoua"... If you dont stick to the pistes there is another crater WSW of the Erg Admer at, I would say about N 23° 44' and E 8° 30' some km north of the well (with or without water...) Tiririne.
It is called Tin Ghoras and has some interesting geological formations
PS: I am never worried in the Sahara, only on the highway from Switzerland to the port in Italy and back!