Mexico City

Mexico City is the capital city of the country of Mexico on Earth. In Spanish it is known as "Ciudad de México." This literally translates to "City of Mexico." By the XXI century Mexico City was already an important city and was the second most populated city in the world.

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. In 2552, during the 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.