The Palace of the Governors was originally constructed in the early 17th century as Spain's seat of government. Located in Santa Fe, New Mexico, the adobe structure, now the state's history museum, was designated a Registered National Historic Landmark in 1960 and an American Treasure in 1999. The Palace of the Governors chronicles the history of Santa Fe, as well as New Mexico and the region. It is known as the oldest continually occupied building the United States. It houses the Fray Angélico Chávez History Library, a non-circulating, closed-stack research facility, preserving historical materials that document the history of the state, the Southwest, and meso-America from pre-European contact to the present.