Mare Crisium
Located in the northeast quadrant of the lunar near side, Mare Crisium is a Nectarian aged basin that spans 740 km. LOLA data reveal that the floor of Mare Crisium is approximately 1.8 km below lunar datum, or "sea level," while the outer rim is about 3.34 km above lunar datum. Lava flow features are prominent enough in this mare that they can be seen in the LOLA topographic data (see arrows in image for locations of some of these features). Two Soviet missions landed in Mare Crisium in the 1960's and 70's. Luna 24 landed in Mare Crisium in 1976 and returned samples from the lunar surface to Earth. Luna 24's predecessor, Luna 15, was less successful. It crash-landed in Mare Crisium in 1969. Mare Crisium is also the location of Luna City - a fictional city featured in the book "The Moon is a Harsh Mistress."