Lake Texcoco, where the famous island city of Tenochtitlán once existed, is no longer a lake. It began being drained in the 17^th century. People hoped that by draining the lake they would get healthy, fertile farmlands. Sadly, that was not the outcome. Now where five interconnected lakes once were, Mexico City and the surrounding suburbs sit. Mexico City is sinking 20 inches a year as the groundwater leftover from the lakes moves deeper underground.