Guishan Island(龜山島) is a small island off the eastern coast of Taiwan in Yilan County(宜蘭縣). It is the only active volcano in Taiwan. Its isolation and natural resources support diverse and rare biology; unique geology give it an iconic turtle shape and many peculiar features.
Guishan Island is known as the guardian of Lanyang Plain(蘭陽平原的守護者). The volcanic island resembles a gigantic turtle protecting the coast. A giant turtle head(龜頭), shell(龜甲), tail(龜尾), and even claw(龜瓜) are identifiable features of the island; the name Guishan Island means “turtle mountain island”. To indigenous tribes of former times, Guishan Island was revered as a deity.
Facing east, the turtle island seems to worship the rising sun every clear morning. Guishan Island has eight famous sights(龜山八景), of which Guishan morning sun(龜山朝日) is the most famous: turtle cliff precipice walls(龜岩巉壁), eyeglass caves stalactite spectacle(眼鏡洞鏡乳石奇觀), submarine hot springs(海底溫泉湧上流), Guishan sulphur smoke(龜山磺煙), Guishan morning sun(龜山朝日), divine turtle wears a hat(神龜戴帽), divine turtle wags its tail(神龜擺尾), and turtle egg wonder(龜卵觀奇).
Vertical rock slabs form the turtle cliff precipice walls(龜岩巉壁) at the turtle’s head and sides. The island’s coastal outline is a mix of steep crag, small gravel beaches, and shallow sea caves.
Volcanic undersea hot springs(海底溫泉湧上流) turn water around the island bright blue. Sulphur smoke(龜山磺煙) from volcanic activity can occasionally be seen as well.
Waves probe sea caves hidden on the edges of the island. The most prominent caves are two large, twin sea caves resembling a pair of glasses and containing stalactites; these are known as the eyeglass caves stalactite spectacle(眼鏡洞鏡乳石奇觀).
Seasonal winds and tides gradually alter the shape of the turtle’s tail as if the divine turtle wags its tail(神龜擺尾). Turtle egg wonder(龜卵觀奇) is the peculiar instance of large, egg-shaped rocks at beaches near the tail. Sometimes clouds hover around the peak of the island; this is is referred to as the divine turtle wears a hat(神龜戴帽).
Many rare native plants prosper on the island. Guishan Island contains the northernmost instances of Taiwan ebony in Taiwan. It is the only place where Chinese fan palm(livistona chinensis var. subglobosa) grows native. Taiwan lily, endemic to Taiwan, thrives all over the island. The steep shape of Guishan Island sustains a primary forest at higher elevations, a secondary forest below, and additional coastal plants.
Animal life also abounds. More than a hundred bird species can be found on this small island; many are migratory birds. The main habitat for the endangered Taiwan flying fox is Guishan Island. Several varieties of frogs and butterflies live on the island, notably the large tree nymph(Idea leuconoe) or “big dumb butterfly”(大笨蝶).
The seas around Guishan Island teem with life as well. In addition to coral reefs around the island, warm waters resulting from undersea hot springs attract ocean life including migrating marine mammals such as killer whales, flying dolphins, bottlenose dolphins, and false killer whales. At the seafloor, hydrothermal vents support an endemic crab species(xenograpsus testudinatus), specially adapted to the sulphur and acidic water surrounding these vents.
Guishan Island was once home to a small village whose population peaked around 700. There was an elementary school, dock, and community of homes. The villagers built a temple dedicated to Mazu in 1845. Eventually the villagers left the island, abandoning their village and temple, and moved to a new community in coastal Toucheng Township. Later, the island became a military zone; military personnel stationed there converted the temple into a Guanyin temple now called Putuo Temple(普陀巖). They also converted the elementary school into soldier barracks and built tunnels equipped with artillery and machine gun positions.
A walking path encircles Turtle Tail Lake(龜尾湖) at sea level. The path includes a statue of Guanyin riding a dragon(乘龍觀音), native vegetation including Chinese fan palm, Putuo Temple, old village sites, and military buildings. A smaller trail branches off to reach a giant Taiwan ebony(毛柿) tree once sacred to island residents. Visitors can also walk through historic military tunnels(軍事坑道) to turrets looking out from the cliffs.
Visiting the island’s summit requires a special permit and a couple hours’ loop hike. The peak offers panoramic views of the island including the turtles head, a small lake(龜首潭), colored ocean waters, and steep cliff formations.