From Halopedia, the Halo wiki
Mtongwe Station was a MagLev train station in operation inside New Mombasa, under the jurisdiction of the New Mombasa Transit Authority.
In 2552, during the Battle of Earth, the station was closed for security reasons after the Covenant forces landed. The MagLev system was one of their targets in the assault.
The station is named after a neighborhood that exists today in the city of Mombasa. The location of the neighborhood is further up the coast from New Mombasa.