New Mexico is a state in the Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also borders the state of Texas to the east and southeast, Oklahoma to the northeast, and shares an international border with the Mexican states of Chihuahua and Sonora to the south. New Mexico's largest city is Albuquerque, and its state capital is Santa Fe, the oldest state capital in the U.S., founded in 1610 as the government seat of Nuevo México in New Spain.