Lake Sfânta Ana (Romanian pronunciation: [ˈsfɨnta ˈana]; Hungarian: Szent Anna-tó, meaning "Saint Anne Lake" in both languages) is the only crater lake in Romania located in the volcanic crater of the volcano named Ciomatu Mare (Nagy Csomád in hungarian) of the Eastern Carpathians, near Tușnad in the Natural Reserve of Mohoș, Harghita County, Romania.