Why did the azrecs build tenochtitlan?

Tenochititlan was the capital and the religious center of the Aztec civilization. The city was located on an island of Lake Texcoco in central Mexico. The legend says that the Aztecs moved from their caves searching for the new home. They awaited the fulfillment of the prophecy that the tribes would built a great city where they see an eagle eating a snake while perched atop a cactus. They saw this vision on Lake Texcoco. The city was founded in the 14th century and remained the capital of expanding Mexican Empire until the Spanish conquerors destroyed it in the 16th century. This eventually led to the final fall of the Aztec empire.