The basalt columns were discovered accidentally during a harbor excavation project in the early 20th century.
The columns are composed of dark, dense volcanic rock contrasted against layers of yellowish-brown tuff sediment.
The hexagonal shape of the pillars resulted from contraction during the cooling of massive lava flows.
The site acts as a geological window into the volcanic activity that shaped the Penghu islands millions of years ago.
The formation is particularly striking when the small puddle in front fills with rainwater, creating a symmetrical reflection.
Daguoye Columnar Basalt is a rare geological formation in Xiyu Township, Penghu, featuring vertical basalt columns formed by rapid cooling of lava during the late Miocene epoch. These hexagonal pillars were originally hidden underground and were only revealed following a land reclamation project during the Japanese colonial period, which unearthed the cliffside while clearing the harbor. The site exhibits a distinctive layering where porous basalt sits atop yellow tuff soil, demonstrating unique volcanic deposition patterns. Rainwater pooling in front of the columns often creates a reflective surface, enhancing the visibility of the rock formations. It is part of the Penghu National Scenic Area and is protected as a significant natural landscape within the archipelago.
From the low-lying area directly in front of the columns, specifically looking for the reflection in the rainwater pool.
Visit during or shortly after a rain shower to capture the iconic reflection in the low-lying basin.
Wear sturdy footwear to navigate the gravel and uneven terrain at the base of the cliffs.
Plan your visit to avoid the intense midday sun, as there is minimal shade along the basalt wall.
Do not attempt to touch or lean on the brittle tuff soil layers beneath the basalt, as they are prone to erosion.
Do not climb, scratch, or remove pieces of the basalt columns as it is a protected natural site.
