So what IS open Monday? The Aztec "floating gardens" at Xochimilco. The " floating gardens" seem to be actually islands. Originally they were chinampas, which were rafts woven of twigs, covered with earth and planted with flowers or vegetables. The rafts often carried a small hut and were propelled about the lake with oars. Gradually the roots of vegetation attached to the lake bottom and the gardens became islands threaded by canals. Now you can go on a boat ride there. Other boats carry musicians, or sell food. They even have grills on the boat so they can sell hot food.