Mexico is located between the Gulf of Mexico and the Pacific Ocean. The United States borders it to the north, and Guatemala and Belize borders it the southeast. Mexico City is its capital. It was formerly the place of several native cultures: Maya, Olmec, Teotihuacan, Zapotec, Toltec, and the Aztec. It was colonized by Spain after 1519. It became free in 1821, and became a republic in 1824.