Firefight: Lost Platoon
From Halopedia, the Halo wiki
Firefight: Lost Platoon is an achievement in Halo 3: ODST when you score over 200,000 points during Firefight on Lost Platoon. It is worth 10 Gamerpoints.[1]
Sources
The symbol for the achievement shows the new mombasa orbital elevator,which probably means it is situated in or around the structure.
