Sinus Meridiani (Latin Sinus meridiani, "Meridian Bay") is an albedo feature on Mars stretching east-west just south of the planet's equator. It was named by the French astronomer Camille Flammarion in the late 1870s. In 1979-2001, the vicinity of this feature (with size about 1,600 kilometers (990 mi) and coordinates of the center 7°07′S 4°00′E / 7.12°S 4°E) was named Terra Meridiani.