Will we ever get sick of skyscrapers? It’s been over 130 years since the world’s first skyscraper went up in Chicago, and there are always plans for taller and taller buildings. At 829.8m/2,722ft, the current record holder is Dubai’s Burj Kalifa, but already under construction is Jeddah Tower in Saudi Arabia, which will rise over 1km above the Earth’s surface. 

But what about going down instead of up? While the focus remains on building high-rise, architects are beginning to look underground for all kinds of projects to make our cities work better. Among the most notable is Elon Musk’s Boring Company, which recently published plans to build a tunnel network under Los Angeles to ease traffic. 

It’s reckoned to be about four times more expensive to build down rather than up, but there are factors that make it uniquely attractive. It’s warmer down there, so heating bills are slashed, and so-called subterranean buildings are less prone to earthquakes.

So as urban populations soar and real estate in cities becomes increasingly expensive, could we be heading for an ever-more-literal concept of ‘downtown’? Here are some of the most intriguing plans for underground construction projects from recent years.