The myriad tunnels under Gaza are best known as passageways used to smuggle goods from Egypt and launch attacks into Israel.

But there exists a second underground network that the Israel Defense Forces colloquially refer to as the “Gaza metro.” It’s a vast labyrinth of tunnels, by some accounts several kilometers underground, used to transport people and goods; to store rockets and ammunition caches; and house Hamas command and control centers, all away from the prying eyes of the IDF’s aircraft and surveillance drones.

Hamas in 2021 claimed to have built 500 kilometers (311 miles) worth of tunnels under Gaza, though it is unclear if that figure was accurate or posturing. If true, Hamas’ underground tunnels would be a little less than half the length of the New York City subway system.

It’s unclear how much the tunnel network would have cost Hamas, which governs the impoverished coastal strip. The figure is likely significant, both in terms of manpower and capital.

Gaza has been under a land, sea and air blockade by Israel, as well as a land blockade by Egypt, since 2007 and is not believed to possess the type of massive machinery typically used to build tunnels deep underground. Experts say that diggers using basic tools likely burrowed deep underground to dig the network, which is wired with electricity and reinforced by concrete. Israel has long accused Hamas of diverting concrete meant for civilian and humanitarian purposes toward the construction of tunnels.

Hamas’ critics also say that the group’s massive expenditures on tunnels could have instead paid for civilian bomb shelters or early warning networks like those across the border in Israel.

Read more about the “Gaza Metro”

CNN