What is the capital of Mexico?

The capital of Mexico is Mexico City, which serves as the political, economic, and cultural center of the country. With a rich history that dates back to the Aztec Empire, Mexico City is one of the largest cities in the world and is known for its significant landmarks, such as the Zócalo, the National Palace, and the historic canals of Xochimilco. Its status as the capital is also vital for governance and administration, as it hosts the country's federal government, embassies, and various international organizations.

In contrast, Guadalajara is known for its cultural heritage and vibrant music scene, Cancun is famous for its tourism and beautiful beaches, and Puebla is notable for its culinary traditions and colonial architecture; however, none of these cities serve as the capital. Thus, Mexico City is the correct answer, as it is uniquely recognized as the seat of governmental authority in Mexico.