|Sianjiaoyu is situated south of Jibeiyu, Baisha Township in Penghu County, and north of Chihkan. This place won its name because it is surrounded by submerged reefs ("sianjiao" in Chinese), but the surrounding underwater resource is so rich, making this a great spot for snorkeling. In addition to the abrasion platform formed by a small rock on the east half of Sianjiaoyu, most of the island is a white sand beach composed of sand grains, shell and coral fragments; from the distance, it looks just like a patch of white sand interlacing with the coastline, simply a fascinating view, and the perfect place to go snorkeling and see groups of tropical fishes and beautiful coral reefs.
Why is the island named "Sianjiao"? "Sian" (dangerous in Chinese) refers to the submerged reefs surrounding the coast, any ship may inadvertently strike a reef and sink, clearly demonstrating how dangerous and scary the massive submerged reefs are underwater; this is why the island is named "Sianjiao", not only does it reveal the true dangers of the coast, but also warn passing-by boats to beware of the waters here.