Mexico City is the remnant of one of the horticultural wonders of the world, the floating gardens (as they are called) of Xochimilco. In Aztec times, the entire city was located in the middle of an extensive swamp, which was partially drained. The resulting system of canals and islands supported the most diverse and elaborate agricultural system ever to have appeared in the world, and many of the varieties of vegetables that are enjoyed around the world today originated or were perfected there. Even today, Mexico enjoys a wider diversity of edible vegetables than the rest of the world combined. This documentary was produced entirely for local consumption and concerns the efforts of the government of Mexico to clean up the pollution of the surviving island and canal complex, a colorful area which is used almost exclusively for fiestas and celebrations of all kinds.