Because of work related to the construction of Metro Line 2 and the acceleration of the sinking of many of the buildings in the historic center, the basic structure of the Palace suffered deterioration, requiring work to secure the building's foundation and supports, especially on the third floor, the central patio and the Patio of Honor.
During this work, the old column bases of the Viceroy Palace were found, two of which were restored where they were found.
They also found old cedar rafters with their brackets, which were used to form the foundation of the first floor.

Recently, excavations in and next to the National Palace have unearthed parts of Moctezuma's "New Houses", the name of the palaces that Hernán Cortés razed to build what has become the current edifice.
Parts of a wall and a basalt floor were found during recent renovations on the building that now houses the Museum of Culture, which adjoins the Palace on its north side.
The wall and floor are believed to be part of Casa Denegrida, or the Black House, which Spanish conquerors described as a windowless room painted in black.
In here, Moctezuma would meditate on what he was told by professional seers and shamans.
It was part of a construction which is thought to have consisted of five interconnected buildings containing the emperor's office, chambers for children and several wives and even a zoo.
More excavations are planned.
Because of work related to the construction of Metro Line 2 and the acceleration of the sinking of many of the buildings in the historic center, the basic structure of the Palace suffered deterioration, requiring work to secure the building's foundation and supports, especially on the third floor, the central patio and the Patio of Honor. During this work, the old column bases of the Viceroy Palace were found, two of which were restored where they were found. They also found old cedar rafters with their brackets, which were used to form the foundation of the first floor.
Recently, excavations in and next to the National Palace have unearthed parts of Moctezuma's "New Houses", the name of the palaces that Hernán Cortés razed to build what has become the current edifice. Parts of a wall and a basalt floor were found during recent renovations on the building that now houses the Museum of Culture, which adjoins the Palace on its north side. The wall and floor are believed to be part of Casa Denegrida, or the Black House, which Spanish conquerors described as a windowless room painted in black. In here, Moctezuma would meditate on what he was told by professional seers and shamans. It was part of a construction which is thought to have consisted of five interconnected buildings containing the emperor's office, chambers for children and several wives and even a zoo. More excavations are planned.
National Palace (Mexico)