How were chinampas built?

The Aztecs would take several large mats of floating plants and stack them on top of each other on a mud flat. Canals were then dug round them for drainage. Waste and compost was added on the top.

They measured 10 x 110 meters and were set out in a grid pattern. They were used to grow root vegetables, grain and fruit.

In 1519 there were about 100,000 people living off 10,000 hectares of chinampa in the Mexican Basin.