Introduction to the East Longitudinal Valley: The East Longitudinal Valley is the topographic landscape of the eastern longitudinal valley of Taiwan. It is sandwiched between the Central Mountains and the Coast Mountains. It is formed by the extrusion of the Philippine Plate and the Eurasian Plate. It spans Hualien and Taiwan. It is named after the two eastern counties, and its location is in the eastern part of the main island of Taiwan, so it is also called the Dongtai Rift Valley. During the Japanese colonial period, it was called the Nakasendo Plains or Nakasendo.