Tenochtitlan was the capital city of the Aztec Empire, founded in 1325 on an island in Lake Texcoco, in what is now Mexico City. It was known for its sophisticated urban planning, impressive architecture, and vibrant culture, featuring temples, canals, and markets. The city was a major political, economic, and religious center until it fell to Spanish conquistadors led by Hernán Cortés in 1521. Today, the ruins of Tenochtitlan are a significant archaeological site and a symbol of Mexico's indigenous heritage.