By Gulf Times Now RIYADH — NEOM, Saudi Arabia’s flagship $500 billion megacity project, has revealed detailed plans for an underground city stretching the entire 170-kilometre length of The Line, in what urban planners are calling the most ambitious subterranean development in human history.
The underground layer — known internally as “The Foundation” — will house a fully autonomous high-speed transit network, climate-controlled logistics corridors, utility infrastructure, and an expansive subterranean public realm featuring parks, markets, cultural spaces, and community facilities.
NEOM’s chief engineer told The Gulf Times Now that construction on the underground network is already underway, with 40 tunnel boring machines operating simultaneously across the project site in the Tabuk region of northwest Saudi Arabia.
“What we are building underground is itself a world-class city,” the engineer explained. “Residents of The Line will rarely need to come above ground for daily needs. Everything — transport, commerce, community — will function seamlessly below the surface.”
The underground city forms a critical component of Saudi Arabia’s Vision 2030 economic transformation agenda, which has earmarked over $1 trillion in investments across tourism, technology, and urban development over the next decade.