China’s rail ambitions just keep growing.

The latest addition to the country’s portfolio is a 277-kilometer (172-mile) high-speed train line along the southeastern coast, connecting the cities of Zhangzhou, Xiamen and Fuzhou, all three of which are in Fujian province.

The maximum speed of the trains along this route is 350 kilometers (217 miles) per hour, according to China Railway, the state railway operator.

The first train on this line debuted on Thursday, September 28, departing from Fuzhou, the province’s capital, at 9:15 a.m.

The new railway currently has 84 bridges and 29 tunnels, plus 20 km (12 miles) of track that goes over the sea, making it the country’s first over-water bullet train.

China Railway says that it used intelligent robots and environmentally friendly corrosion-resistant steel to build out the overwater rail sections.

The new line is just one of many infrastructure projects touted by the Chinese government in 2016 when the “Eight Horizontal and Eight Vertical” rail initiative was announced. State-run media outlet Xinhua notes that ground transportation in Fujian province has been challenging due to its mountainous terrain.

Fujian province is also significant for being the closest part of mainland China to the self-governing island of Taiwan. Xiamen is just two and a half miles (10 km) across the Taiwan Strait from Kinmen, the westernmost region of Taiwan.

China’s ruling Communist Party claims Taiwan as its own territory, despite having never controlled it.

According to Xinhua, the Communist Party released a circular earlier this month calling for “facilitating better connectivity and integration between Fujian and Taiwan.”

A controversial proposal from a group of eight local government councilors in Kinmen earlier this year suggested building a literal and metaphorical bridge across the strait. The plan would turn Kinmen into a “peace island,” or a sort of DMZ between Taiwan and China.