Caipu'ao Geopark is Taiwan's only coastal geological landscape area dominated by volcanic rhyolite. The rock surfaces display distinct flowing bands; the grey-white to pink coloring varies with mineral composition, left by volcanic magma that erupted and cooled rapidly. The coastline is irregular, with multiple bays and inlets. From April to August each night, this area is also one of the locations where the bioluminescent "blue tears" dinoflagellates can be observed.
Highlights of Caipu'ao
Rhyolite is an acidic extrusive volcanic rock. When magma erupts onto the surface and cools rapidly, minerals that have not had time to crystallize form a glassy matrix; the flow also produces banded textures known as "flow lines" (rhyolite). The geological foundation of the Matsu area is primarily granite, but here at Caipu'ao a special geological structure has preserved a rhyolite stratum — unique in all of Taiwan and of significant educational value for geology.
The rock color shifts from grey-white to pink depending on silicate mineral content; the direction of the banding twists with geological structure. Combined with the sea-eroded grooves and sea stacks sculpted by wave action, the entire coastline resembles an abstract geological canvas. Each year from April to August, if sea conditions are stable, bioluminescent dinoflagellates may appear in the nearshore waters of the bay, creating the blue tears phenomenon — but whether they appear depends on that year's sea conditions and cannot be guaranteed.
How to Make the Most of Your Visit
Practical Information
Getting There and Time Needed
- To reach West Juguang, take a ferry from Fuao Harbor on Nangan. Schedules are affected by weather — confirm with Matsu Shipping Company.
- Caipu'ao is on the southern side of West Juguang Island, about a 10- to 15-minute scooter ride from Qingfan Harbor. The reef terrain requires non-slip shoes for walking; some sections are steep.
Nearby Connections
- Can be combined with Kunqiu Beach (Square Waves) for a West Juguang day trip: morning at Kunqiu, afternoon at Caipu'ao. If you stay overnight on West Juguang, you can add a blue tears watch session.
- During the April-to-August blue tears season, all of Matsu's islands offer viewing opportunities. Nangan and Beigan also have designated viewing spots — can be integrated into an island-wide itinerary.
Source: Matsu National Scenic Area Administration geological landscape descriptions, Lienchiang County Government tourism information. Photos pending Dio's on-site shots.