Humans have survived and thrived in Mexico City by using technology to create greater access to land. When the Spanish conquered the Aztec capital, Tenochtitlan, in the 16th century, they built Mexico City by draining the lakes and filling in the lake water to create more arable land for agriculture. This technique of land reclamation has continued to be fundamental to human civilization in Mexico City. The construction of canals and tunnels to transport water out of the valley also has supported land reclamation. The construction of Chinampas, artificial islands to grow food and hillside terraces for water storage and agriculture, is an additional innovative technique that has created more productive land that allows for human survival.