In view of their possible utility in connection with future exploratory surveys, I give below a list of some of the more important of the positions which I have recently determined by astronomical observation in the southern part of the Libyan Desert, with brief descriptive notes on the places to which they refer. The observations were made whilst accompanying H.R.H. Prince Kemal el Din Hussein on his exploratory motor-car expeditions of 1923, 1924, and 1925. The longitudes of Qasr Farafra, Abu Mungar, Pottery Hill, and Regenfeld depend on the transport of a box-chronometer; the others on wireless time-signals from Europe. The positions of peaks were found by triangulation from the actual observation-spots. The altitudes of camps are from careful barometric determinations; those of the peaks depend on trigonometric levelling from the camps. _Altitude _Place._ _Lat. N._ _Long. E._ above sea. Metres._ ° ′ ″ ° ′ ″ Merga, Camp 600 metres S.W. of west 19 2 29 26 18 32 526 corner of salt lake. (Lake surface is 17 metres below level of camp.) Bir Terfawi, Camp close to well and 22 55 12 28 52 51 244 palms Gebel Kissu, Summit 21 34 59 25 8 26 1726 Gebel Owenat, highest point 21 54 34 25 0 47 1907 „ „ remarkable triple peak 21 53 51 25 1 39 1718 „ „ S.W. peak 21 49 35 24 53 52 1450 Chunk Hill, Summit 21 52 46 25 13 56 985 Owenat, Camp 600 metres S.E. of 21 48 35 24 51 45 568 western spring, on plain at foot of mountain Owenat, Camp at mouth of gully, 21 53 8 25 7 58 626 about 800 metres S.S.E. of eastern springs Gebel Kamil, Summit (160 metres 22 16 31 26 38 11 800 above plain) Regenfeld, Rohlfs’ cairn of 1874, 25 10 49 27 24 22 470 rediscovered 1924 Pottery Hill, Summit (39 metres 24 26 27 27 38 54 506 above plain) Sheb, Camp close to well, 240 22 19 48 29 45 46 228 metres N.N.E. of fort Mut, Government Rest-house 25 28 37 28 58 24 119 Abu Mungar, Camp at small ruin, 400 26 30 22 27 35 29 117 metres E.S.E. of well Qasr Farafra, Camp E. of village, 27 3 26 27 57 52 90 200 metres S.W. of Tomb of Sheikh Dakhil