This plaza is also known as the "zocalo" This enormous paved square, occupies the site of the ceremonial center of Mexico-Tenochtitlan, the capital of the Aztec Empire. Ever since the time of Emperor Moctezuma, the area was surrounded by palaces, temples and other structures. El Zócalo is used for government/political rallies, protest marches, sit-ins, concerts and other festive events too all round year. ....Today is the largest public square in the Western Hemisphere, and the third one in the world (after the Tiananmen Square in the center of Beijing and the Red Square in Moscow). It is the main square -its formal name is Plaza de la Constitución- and forms the heart of the city ever since the Aztec rule. ..