Inside The Octagon: The Largest Defence Complex on Earth

The world's largest military headquarters is no longer the Pentagon. It's The Octagon, a sprawling military complex in Egypt's New Capital that now serves as the headquarters of the Egyptian Armed Forces.

Construction began roughly a decade ago, though the project attracted international attention years earlier as satellite images revealed a vast development east of Cairo before officials disclosed its purpose. Covering 22,000 acres, The Octagon occupies just over half the land area of Washington, DC, making it the world's largest military headquarters by site area. The complex comprises 13 operational zones housing the Ministry of Defence, Armed Forces command, data centres, secure communications networks and cybersecurity infrastructure.

Unlike the Pentagon's single five-sided building, The Octagon consists of ten octagonal buildings arranged around a central plaza, with the design said to represent the branches and institutions of the Egyptian state.