Ara is a Southern Hemisphere constellation otherwise known as the Altar. It is one of the 48 Greek constellations originally described by the 2nd century astronomer Claudius Ptolemy (Wikipedia). Ara remains one of the 88 modern constellations defined by the International Astronomical Union (Wikipedia).
Ara (abbrev. = Ara; genitive = Arae) covers 237 square degrees or 0.58% of the celestial sphere making it the 63rd largest constellation. It contains 71 stars brighter than apparent magnitude 6.5, the brightest star being Beta Arae.