Chinampas are a result of a farming technique on raised segments of land that have been artificially constructed in lakes (Hassig 1985). They are popularly, and mistakenly called floating gardens. The word chinampa comes from the Nauhatle words chinamitl (reed basket) and pan (upon), a good description of their building methods (Werner 1992). There is some debate on when chinampas were first used. Hodge and Smith (1994) suggest that they began in the early Aztec period, but only later did the use of chinampas become widespread. Chinampas were primarily found in the lake area around Tenochtitlan. The southern chinampas contributed 3,335 metric tons to Tenochtitlan in tribute and 16,555 metric tons made its way to the market (Berdan 2005). Lake conditions in the more saline lakes hindered the use of chinampas, although they still did exist around Xaltocan and Zumpango (Hassig 1985). Chinampas were used extensively at the Basin of Mexico at the time of the conquest (Hassig 1985). 
Fig 3: Chinampa areas in the Valley of Mexico (Diaz del Castillo 1974)