The green algae phenomenon is strictly seasonal, occurring primarily between March and May before the intense summer sun causes the seaweed to wither.
The parallel stone trenches are remnants of volcanic lava flows that cooled and were subsequently eroded by wave action over centuries.
The site is often referred to as the 'Green Reef' by local residents and photographers.
The geological composition is primarily andesite rock, which is resilient enough to form deep, consistent channels rather than eroding into jagged boulders.
Laomei Beach is renowned for its distinctive volcanic rock trenches that become carpeted in bright green sea lettuce algae each spring. The geological formations consist of parallel rows of volcanic tuff created by past eruptions of the nearby Datun Mountains. As the tide recedes, these trenches reveal moss-covered stone ridges stretching toward the ocean. It is one of the few places in Taiwan where such a regular, geometric erosion pattern is visible. The beach is situated on the northern coast of New Taipei City in Shimen District. Visitors walk across the sand to access the reef section during low tide. The coastal area remains a protected natural site influenced by the East China Sea currents.
From the sandy shoreline looking toward the water, framing the receding tide as it cascades over the parallel green stone rows.
Consult local tide tables before visiting, as the green trenches are only visible and accessible during low tide.
Wear non-slip footwear, as the algae-covered volcanic rocks are extremely slippery and treacherous to walk on.
Bring a polarizing filter for your camera to reduce glare from the water and enhance the vibrant green colors of the algae.
Do not visit during high tide, as the reefs will be submerged and the strong coastal currents make the water dangerous.
The green algae is a seasonal event, largely absent outside of the spring season.
Do not step on or pick the green algae, as it is fragile and essential to the local ecosystem; keep the beach clean of trash.
