Casa Denegrida de Moctezuma
Mexico City, Mexico
The Casa Denegrida de Moctezuma (The Black House of Moctezuma) was part of the royal palace and chambers of Tenochtitlan's ninth tlatoani Moctezuma II. The Black House, or more accurately the black room, was a windowless room fully painted in black where Moctezuma would meditate. The floor was made of large irregular black basalt slabs.
Archaeological site data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).