The modern-day archeological site lies just to the northeast of the Zocalo , or main plaza of Mexico City , in the block between Seminario and Justo Sierra streets . The site is part of the Historic Center of Mexico City , which was added to the UNESCO World Heritage List in 1987 .
The modern-day archeological site lies just to the northeast of the Zocalo , or main plaza of Mexico City The site is part of the Historic Center of Mexico City , which was added to the UNESCO World Heritage List in 1987 .