Town in the red desert grew around the oasis. After under the city revealed a cave, with a long-dormant underground volcano. Later, people learned that clean water that feeds the oasis is the result of careful filtering, provide the porous solidified lava. Since then, the city began to grow and surprisingly for the desert - to bloom. If the people of the great lakes Plains provided neighbors with water, which was long and hard to supply, the inhabitants of the state in the red desert could give neighbors a light volcanic rock, which could clear huge amounts of water already in place. Very rarely I go to VC and am very glad that the post with the contest caught me, though late. Hope I can. I want to add a lot, but one job does not fit.