From Halopedia, the Halo wiki
Lake Autolycus was a lake on Luna in the mid-22nd century. In August of 2167, the leader of the Koslovics, Vladimir Koslov, and his family, were killed in a bombing near this lake. While the UNSC denied involvement, many believed that the Friedens, which were also at war with the Koslovics, were not capable of carrying out such an attack.
The term "Lake" does not necessarily refer to a body of water; in the context of discussing lunar geography, the term Lake (or Lacus) is used to describe basaltic regions smaller than lunar seas (or Maria), with real-world examples including Lacus Autumni ("Lake of Autumn") and Lacus Doloris ("Lake of Sorrow") - among others. No current real-world Lacus bear the name Lake Autolycus, though the location does share its name with the Autolycus impact crater - it is unknown whether this location's namesake refers to a Lacus or a physical body of water present on the moon by the 22nd Century.
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