A 400-metre cube in the Saudi desert — large enough to fit 20 Empire State Buildings inside. The centrepiece of the New Murabba district in Riyadh.

Announced in 2023, the Mukaab is a 400m x 400m x 400m cube containing a spiralling immersive tower inside called the "Mukaab Experience." The interior will house hotels, retail, and entertainment. It's essentially a city within a building.