In 1610, construction of the Palace of the Governors began as a section of the Casas Reales de Palacio, or royal houses. Built around Santa Fe's plaza, the Casas Reales included the governor's living quarters, the jail, the town council, and the parish church. The plaza was completely enclosed with watchtowers on the corners and featured some two-story buildings. Over time, the towers disappeared and the governor's residence lost its second floor. At the end of the 1600s, a new presidio, or fortress, was built, incorporating the old residence and extending two blocks north and two blocks west of the plaza. After Mexican independence in 1821, the Casas Reales-presidio was renamed el Palacio del Gobierno, or Government Palace, which non-Spanish speakers mistranslated as Palace of the Governors. Today it is the oldest public building in the U.S. and serves as New Mexico's History Museum.
