Part of the Mexica emperor palace, were used to cement the New Spain Mint House.

During integral restoration program at the National Museum of Cultures (MNC), of the National Institute of Anthropology and History (INAH), excavations allowed the discovery of structures that were part of Moctezuma palace, known as New Houses, according to specialists.
The 13 Moneda St. plot, at Mexico City Historical Downtown, is considered of high archaeological potential. Based on this, field seasons took place to discover what the core of this building hid, with the aim of corroborating historical information about old buildings that remained under the present ones.
According to Elsa Hernandez Pons, woman in charge of archaeological works at 13 Moneda St., based on knowledge about potential findings, radar explorations using X-ray spectrum took place, which allowed to detect, under some zones of the museum, Prehispanic and Colonial structures that served as foundation for later constructions.
Based on 16th century historical documents, we reached the conclusion that Prehispanic walls and cementations found were part of the residential complex known as New Houses of Moctezuma, conformed by five intercommunicated palaces constructed over great platforms, confirmed the investigator.
Among the findings, the one located at the flank of Greece and Rome Hall outstands. According to Hernandez Pons, it corresponds to Casa Denegrida, or Blackened House, called after the black color and absence of light and windows that presented. Moctezuma, el Joven, retired to meditate to this place.
Great irregular black basalt slabs conformed the floor of the place -over which Mint House was constructed- described by conquerors as "a black house; a room without windows and painted black".
Colonial Mint House foundations, on their early and late stages, were also found. At the Ancient monoliths gallery of the museum, evidence of original floors of the first Mint House founded in America was discovered.
Flattening of the same hall walls was retired. This revealed closed accesses that connected different spaces. No archaeological vestiges were found, although excavations reached 4.4 yards of depth.
Among Colonial discoveries, a wall stands out: according to the specialist, it corresponds to the 16th century first building’s façade.  Prehispanic materials were reused: cut stones from the former palace structures are part of this wall.
 "Between 1731 and 1734, the Mint House is reformed. The enlargement includes the façade conserved to the present day, and other elements. In 1762 the area known as Los Comunes, the commons, or Baths, underwent an extension".
Remains of 1762 latrines and other sanitary facilities, as walls, water-drainages and clay pipes that still can work were found, but the area conservation state is poor, being this the reason of its access restrain.
The palace where Moctezuma Xocoyotzin lived and dispatched during his mandate (1502-1520), originally occupied the block that is now shared by National Palace and National Museum of Cultures. Today, Corregidora St., Correo Mayor St., Moneda St. and Plaza de la Constitucion surround it.
The building that undergoes restoration, has been in continue use for more than 500 years; the first Mint House of America, former National Museum and INAH’s National Museum of Cultures, not only locks up cultural expressions of different civilizations from the world, but also maintains important historical past of a nation that keeps changing configuration every day.