Very steep rock-and-forest mountainsides north of Taroko descend directly into the sea from several hundred metres' altitude. That means that roads and railways here are funnelled mostly through tunnels, but where they emerge briefly to cross side valleys or to run along ledges, drivers can catch glimpses of the coastline formations stretching far ahead.
The main 'cliff' zone stretches 21km between Chongde and Heren. Coming from Hualien on Hwy 9, the first cliff-viewing point is right at the Km176.4 lay-by (no coaches). If you continue through the long tunnel and stop at Km174.6, there's a much bigger parking area from which it's a six-minute walk down a section of old road to another series of views. If you're not driving (or on a coach tour), an original alternative offered by Hualien agencies is to join a sea kayaking group or to quad-bike along the beach from Chongde.
