In one of the most ambitious feats of urban planning to date, Chinese officials have announced plans to merge 9 sprawling cities together into one giant megacity. The super-city’s population will be a staggering 42 million — making it the largest city on earth by far.

The megapolis will span 16,000 square miles across China’s Pearl River Delta, making it larger than Greater Tokyo, and 26 times the size of Greater London. The plan is called, somewhat ominously, the “Turn the Pearl River Delta Into One,” according to London’s Telegraph. The cities that the plans seek to unite comprise a major manufacturing region for mainland China; in total, it generates some 10% of the nation’s economy.

The mega city will be connected by an intricate network of rail lines and other transportation; over 150 major infrastructure projects will be launched over the next 6 years to link the energy, water, transit, and sanitation needs of each of the existing 9 cities populations. Over 3,100 miles of rail will be laid to form 29 different lines, which will make moving about the massive urban area relatively easy. The projects combined will cost a projected $196 billion.

Ma Xiangming, the chief planner at the Guangdong Rural and Urban Planning Institute, told the Telegraph that “the idea is that when the cities are integrated, the residents can travel around freely and use the health care and other facilities in the different areas.” Indeed. China’s urban planners must read the Utopianist — just last week, we featured a plan to create such vertical megacities to efficiently house its booming population. This blueprint for the Pearl River area looks strikingly similar.

And impressive as all of this is, it may simply be a model-scale test run of things to come — plans are already in the works to create another megacity. That one, which would encompass an area known as the Bohai Economic Rim, would give rise to a city that’s nearly incomparably vast: population 280 million.

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