Opportunities

Although the granite is a useful resource for building dwellings, the barren land and a lack of drinking water mean life is hard on the island. Sweet potato porridge is still the predominant local dish, because the arid land is only suitable for the cultivation of crops that can endure drought - mainly sweet potatoes and peanuts.

"The poor life on the island forced young people to leave and look for work outside, while the old people stayed and fished for a living," said Chen Yuqin, head of Beigang.

In addition to fishing and shipping, tunnel construction has long been an employment mainstay. The unyielding terrain meant the people of Pingtan had to dig underground chambers to store goods and food, so they became adept at tunneling.

They are still renowned in the industry, and many locals run construction companies that specialize in tunneling projects.

"By the 1990s, about 80 percent of all the tunnels in China had been dug by Pingtan people. Every family has at least one member in the industry," said Chen, who used to run his own tunneling company.

"People earned a lot from digging tunnels, but they had to leave their homes, so many houses in the village were unoccupied or even abandoned."

Pingtan is the closest part of the Chinese mainland to Taiwan - the city of Hsinchu is 68 nautical miles (126 kilometers) away across the Taiwan Straits. In the 1960s, when cross-Straits relations were tense, the county became the front line for troops, and local people were encouraged to dig bomb shelters and underground grain stores.

In recent years, though, Taiwan's close proximity has brought opportunities for Pingtan's residents.

In 2011, a direct ferry route was launched between Pingtan and Taiwan, with a journey time of three hours. In 2015, the county was designated a free trade zone, with the emphasis on attracting investors from Taiwan.

In 2016, the central government decided that the county would be expanded into an international tourism zone.