Mexico City
From Halopedia, the Halo wiki
Mexico City is the capital city of the country of Mexico on Earth. In Spanish it is known a "Ciudad de Mexico."
Background
Second Battle of Earth
It was the location of Base Segundo Terra, a major facility for the United Nations Space Command and 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.