Cassandra Garduño squinted in the sunlight, her pink boots smudged by dirt as she gazed out over her family's chinampa — one of the islands first built up by the Aztecs with fertile mud from the bottom of a lake that, later drained, would one day become Mexico City. Food from these islands has fed people for hundreds of years, but the chinampas are under threat from urbanization. The produce grown here doesn't fetch much money, and many families are abandoning the ancient practice to rent out or sell their land for more lucrative uses such as soccer fields.