Mare Frigoris (the "sea of cold") is a lunar mare located just north of Mare Imbrium, and stretches east to north of Mare Serenitatis. The mare is in the outer rings of the Procellarum basin. The basin material surrounding the mare is of the Lower Imbrian epoch, while the eastern mare material is of the Upper Imbrian epoch, and the western mare material is of the Eratosthenian epoch.
The dark circular feature just to the south of Frigoris is the crater Plato.
This area of the Moon featured prominently in 'Behemoth', the second episode of the 1973 BBC science fiction mini-series Moonbase 3.