Weizhou Island sits in the Gulf of Tonkin about 50 kilometres southwest of Beihai, and it is geologically singular: China's youngest volcanic island, shaped by eruptions as recently as seven thousand years ago, its basalt cliffs and columnar rock formations giving the coastline a character entirely different from anywhere else in Guangxi. The island covers about 25 square kilometres and is ringed by coral reefs that rank among the healthiest in the northern South China Sea — the warm, clear water and relative isolation from industrial development have kept them in condition unusual for this part of the world.
The coral reefs make Weizhou an actual diving and snorkelling destination rather than an aspirational one, with turtles, rays, and a variety of reef fish accessible from the shore. The Beihai Weizhou Volcano National Geopark preserves the volcanic landscape itself, where the rock formations have the otherworldly quality of cooling lava frozen mid-flow. Two French Catholic churches built in the late nineteenth century stand in Shengtang Village — Gothic brick structures with pointed arches that have survived remarkably well and look genuinely strange amid the fishing boats and basalt outcrops. The island hosts 147 species of birds and has been designated an Important Bird Area.
Weizhou is populated and functional: fishing villages, some seafood restaurants, motorcycle taxis to get between attractions. It is not a resort island and the accommodation is modest, but that is precisely what makes it interesting. The combination of volcanic landscape, colonial churches, working fishing culture, and accessible marine environment is unusual enough that a night or two here justifies the ferry from Beihai.
Ferries run from Beihai's North Sea Ferry Terminal in roughly an hour. Booking ahead is advisable during Chinese holidays when the island fills with domestic tourists from Guangxi and Guangdong.