The 'whale' shape was reinforced by a collapse that occurred several decades ago, altering its original appearance.
The basalt here is part of the volcanic activity that occurred in the Penghu region approximately 8 to 17 million years ago.
The surrounding terrain contains fossils of marine life embedded within the sedimentary layers near the basalt.
The name Whale Cave (Whale Grotto) originates from its resemblance to a beached whale skeleton when viewed from the sea.
The islet is connected to Xiyu Island by the Xiaomen Bridge, allowing for terrestrial access.
Whale Cave is a massive natural basalt archway formed by sea-water erosion on the northern coast of Xiaomen Islet in Penghu, Taiwan. Originally a basaltic cliff, the landform underwent continuous wave erosion that eventually carved a hole through the rock, creating its distinctive whale-like silhouette. The site features columnar basalt formations, a geological characteristic of the Penghu archipelago. Surrounding the arch, the landscape includes a wave-cut platform that is frequently exposed during low tide. The area is part of the Penghu National Scenic Area and is integrated into the Penghu Geopark network. Vegetation near the site is sparse due to the saline environment and high wind exposure. Visitors access the arch via a paved trail leading from the nearby visitor center. The cavern serves as a primary example of coastal geomorphology in the South China Sea region.
The elevated viewing platform on the trail provides the best angle to capture the full arch silhouette against the ocean.
Wear sturdy, non-slip footwear as the basalt rocks around the wave-cut platform can be sharp and slippery.
Check local tide charts to ensure you visit during low tide to safely access and walk along the coastal platform.
Bring sun protection, as the area is completely exposed with virtually no shade.
Do not attempt to walk through the arch during high tide or strong monsoon winds, as waves can surge through the cavern unexpectedly.
Do not climb or deface the fragile basalt rock structures; stay on marked paths to protect the geopark ecosystem.
