After the Conquest, a small chapel dedicated to the Archangel Michael was built on the hill by Claudio de Arciniega in the middle of the 16th century. In the 18th century, the Spanish built the Chapultepec Castle, which initially was a summer retreat for viceroys. After the Independence, the Castle remained for the elite, becoming the official residence of Mexico's heads of state, including the Emperor Maximilian, who had the Paseo de la Reforma built to connect this area with the historic center of the city. During this time, the Castle and the gardens around it were enlarged and embellished a number of times, giving the Castle a floorspace of . The most outstanding of the patios and garden is the Alcázar. In 1940, the president's residence was moved to the nearby Los Pinos complex, and the castle was converted into the National Museum of History, under the auspices of the federal government, along with the rest of the hill. The museum contains twelve rooms which are open to the public, many of which as they were when the Emperor Maximilian lived there. It also contains a collection of furniture from the colonial period to the 19th century, utensils, suits, coins, manuscripts, sculptures in clay ivory and silver, and many other art works. A number of items belonged to figures such as Miguel Hidalgo y Costilla, José María Morelos y Pavón, Agustín de Iturbide, Benito Juárez, Emiliano Zapata, and others. In addition, there are murals by José Clemente Orozco, David Alfaro Siqueiros and Juan O'Gorman. At the foot of the hill, there is a large monument to the Niños Héroes (also called the Altar a la Patria), who reportedly threw themselves to their death at the Castle rather than surrendering to invading US troops in 1847. This monument consist of six marble columns surrounding a mausoleum with the remains of the six cadets, and a figure of a woman who represents Mexico.