Digging deep to explore subterranean space

The increasing scarcity and soaring cost of land for development has prompted a rising number of cities to consider underground construction projects. Xu Wei reports.

As land resources become increasingly scarce amid China's urban sprawl, local authorities have resorted to a new frontier for space: the world below our feet. A number of cities have decided to tap this underground space to reduce the mounting pressures on available land in high-density urban areas.

In late December, Wuhan, the capital of Hubei province, announced that construction had started on one of the country's largest "underground cities".