Just north of Hualien on Taiwan’s east coast was a mountainous region with fast flowing rivers, waterfalls, steep gorges and lush forests.
I arrived at Taroko’s Yanzikou trail, also known as Swallow Grotto because of the mainly Pacific swallows that darted over the Liwu River. Downstream the gorge was wider and made up of gneiss. Upstream the gorge was narrower and marble.
Another of Yanzikou’s features was potholes. They were caused by sand in the water rubbing against the marble or by groundwater that seeped through cracks. Higher potholes indicated where the Liwu River once flowed before cutting deeper into the gorge.