When Spanish conquistadors under the command of Hernan Cortes landed in Mexico in the 16th Century, they encountered the unique indigenous empire of the Aztecs.

The capital city of this vast, wealthy empire was a floating metropolis known as Tenochtitlan. This video reveals how the Aztecs' mastery of engineering allowed them to create this fascinating marvel of Mesoamerica.

Video script: Ed Barrett, from the Department of Science and Technology Studies, University College London.