The two buildings, if completed, will reach 1,600 feet into the sky—likely near 150 stories—and will run parallel for 75 miles. The price tag on the complex? A jaw-dropping trillion dollars.

The Mirror Line is the pet project of Saudi Crown Prince Mohammed bin Salman, reports the Wall Street Journal.  It will house roughly 5 million people and will include a high-speed train under the buildings to let people move about in it.

Other amenities include a sports stadium, which will stretch 1,000 feet in the sky; a yacht marina; and vertical farming to ensure residents have enough food. Residents will pay a subscription to be served breakfast, lunch, and dinner.

The Mirror Line will consist of two mirrored buildings crossing mountain and desert terrain, connected by walkways. And it’s part of a development called Neom, which Prince Mohammed envisions being roughly the same size as Massachusetts.

Planners don’t have long to design the structure. Saudi officials have given then a completion deadline of 2030.

Financing a project of this scale, of course, is dependent on financing, which will require demand for Saudi oil, something that has been on the wane in recent years, given the country’s human rights record (as well as the killing of journalist Jamal Khashoggi four years ago). But as Russia’s invasion of Ukraine drags on, Western nations are reconsidering their boycotts, even as oil prices increase.

Prince Mohammed first unveiled plans for this linear city last January, saying it would have no cars and zero pollution. He has likened Neom to a modern version of the Egyptian pyramids.