River and Trees. The origins of Taroko - Taiwan sits on a fault line which actually raises the limestone mountains 1/2 a centimeter each year. At the same time, the Liwu river erodes the canyon floor, deeping the canyon and tossing boulders through the riverbed. As for the marble - just as coal turns to diamond, so limestone turns to marble under great pressure. Thus the largest source of marble in the world, buried beneath the mountains. . .