Mexico City
From Halopedia, the Halo wiki
Mexico City is the capital city of the country of Mexico on Earth. Wic was not invaded.
Background
Second Battle of Earth
It was the location of Base Segundo Terra, a major facility for the United Nations Space Command Defense Force in the region[1]. In 2552, during the Second Battle of Earth, SPARTAN-104, SPARTAN-058, and SPARTAN-043 used the Base Segundo Terra as a staging point to attack the Covenant incursions on Havana and the Yucatan Peninsula.