The main square of Mexico City, known as the Zocalo, occupies a central place in the make-up of the city, the nation, and even the national identity of Mexico. As we all know, the conquistadors built Mexico City on the site of Tenochtitlán, the capital of the Aztec empire. Indeed, the ruins of the Great Temple of the old city lie hidden under the square itself. This essay deals with the moment when the native past began to emerge from beneath the plaza, when a viceroy had the ground paved, and undertook a series of public works to solve the problems of drainage and water channelling which had existed throughout the history of the city. In his effort to modernise, the viceroy brought his contemporaries face to face with a long-buried past. For amidst the construction work two great archaeological pieces were discovered in 1790. These findings were subsequently studied by the multi-talented Creole, Antonio León y Gama, one of the most steadfast representatives of the Enlightenment in New Spain. By examining elements of Leon y Gama's work, I want to do a bit of historical excavation myself and reveal the existence of what we might describe, following Mary Louise Pratt, as a contact zone—one in which contemporary tools for investigatively ordering time and space were brought to bear on natural and cultural phenomena alike, in order to situate Mexico and its cultural heritage historically as well as geographically.