Taroko Gorge, one of Taiwan's most spectacular national parks, is located along the precipitous northeast coast of the island of Taiwan. The gorge exposes the core of one of the best examples of an active arc-continent collision in the world. In this area, the Luzon volcanic arc, which extends southward to the Philippines, is colliding with the Eurasian passive continental margin at about 8 cm per year. As a result of the collision there are at least a hundred peaks over 3000 meters in elevation, with many reaching nearly 4000 meters. Taroko Gorge cuts through this spectacular topography, exposing highly deformed dark gray marble that originally formed as limestone on the Eurasian continental shelf about 230 million years ago. During the collision the limestone was affected by high-grade metamorphism, and then progressively eroded as the Taiwan mountain belt emerged above sea level a few million years ago. The high uplift rates and heavy rainfall that characterize Taiwan have combined to produce one of most popular tourist destinations in the western Pacific.