Firefight: Lost Platoon

Firefight: Lost Platoon is an achievement in Halo 3: ODST. It is awarded for scoring over 200,000 points during a match of Firefight on the map Lost Platoon. It is worth 10 Gamerpoints.

Trivia
The symbol for the achievement shows the New Mombasa Orbital Elevator, which probably means the level is situated in or around the structure.