Mare Vaporum (the "sea of vapors") is a
lunar mare located between the southwest rim of
Mare Serenitatis and the southeast rim of
Mare Imbrium. The lunar material surrounding the mare is from the
Lower Imbrium[?] epoch, and the mare material is from the
Eartosthenian[?] epoch. The mare lies in an old basin or crater that is within the
Procellarum basin. To the south of the mare is a light colored thin line. This feature is
Rima Hyginus[?]. The mare is bordered by the mountain range
Montes Apenninus.