Mensa is the darkest of all constellations. It is the only one of the 88 constellations that has no star brighter than the fifth magnitude. North of it you can see the Magellanic Cloud.
How to spot Mensa
After the invention of the telescope, the French astronomer Nicolas de Lacaille named some constellations of the southern hemisphere that had not been recognized before. Unlike the 48 constellations of antiquity, which bear the names of mythological figures, he often used the name of technological novelties for the new constellations. With this constellation, he wanted to remember the Table Mountain ("Mons Mensa") in South Africa, which was often clouded.