Tenotchtitlan was the capital of the Aztec empire, now Mexico City. The Aztecs had a very advanced culture with their own system of mathematics, astronomy, and religion. The Aztecs believed that there were three places where the spirits of the dead rested. The warriors who died in battle went to the paradise of the Sun God. Those who died drowning went to the paradise of the Rain God, Tlaloc, and those who died by natural causes went to Mictlán. Aztecs viewed death as the continuation of life. After the Spanish invasion, Día de los Muertos (Day of the Dead) became a fusion of Aztec beliefs and Christian traditions.