11.   From dry lake beds to mining trails and wildflower-filled canyons, the camping is remote and there is single-track riding for skilled bikers.

12.   Four columns planted in the lake bed support the structure.

13.   Global Surveyor has observed layers of sediment filling vast craters near the Martian equator in patterns similar to those found in lake beds on Earth.

14.   Here, oxidation in the clay of the ancient lake bed has created giant splotches of color on a cliff face.

15.   In the dry winter months the prevailing southerly winds swirl over the lake bed, lifting its foul dust and spreading it over the rest of Mexico City.

16.   Mexico City is unusually vulnerable to earthquakes because it lies on a lake bed of shifting earth that geologists describe as jelly-like.

17.   Now the parched lake bed is an open-air dump cluttered with mountains of burning tires, construction rubble, factory waste and rotting trash.

18.   Rather than digging for minerals, the miners leach them out of the soil with water, using a series of canals that cut across this ancient lake bed.

19.   Skirt the dry lake bed on the north, or right, side for about four miles until you spot the kite buggiers.

20.   Suddenly, a dust storm rolled over us, filling the air with choking white dust loaded with alkali from the lake bed.