Lebanon’s Rocky Terrain Makes Tunnel Digging Easy for Hezbollah

Entrance to a border tunnel destroyed by the Israeli army at the Lebanon border in 2019 (AFP)
Entrance to a border tunnel destroyed by the Israeli army at the Lebanon border in 2019 (AFP)
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Lebanon’s Rocky Terrain Makes Tunnel Digging Easy for Hezbollah

Entrance to a border tunnel destroyed by the Israeli army at the Lebanon border in 2019 (AFP)
Entrance to a border tunnel destroyed by the Israeli army at the Lebanon border in 2019 (AFP)

Hezbollah is using Lebanon’s rocky landscape to dig tunnels in mountains and valleys, aiming to hide from Israeli airstrikes and launch attacks from what are considered safe areas.

Due to limited details on how these tunnels are built or their specific purposes, experts believe Hezbollah uses this method as an alternative to open combat under Israeli aircraft.

Retired Brig. Gen. Fadi Daoud told Asharq Al-Awsat that Hezbollah’s tunnel strategy forces Israel into difficult underground warfare, a challenging type of combat in military terms.

Daoud explained that tunnel networks “take away key advantages from the enemy.”

“Even though the Israeli military has a powerful air force for reconnaissance and airstrikes, tunnels prevent them from seeing targets. This has reduced the effectiveness of the air force and limits its ability to maneuver,” said Daoud.

He also noted that the Israeli military is prepared for tunnel warfare, with weapons like the Massive Ordnance Air Blast (MOAB) bomb, sponge bombs, and Bunker Buster bombs, which can destroy tunnels up to 60 meters deep. However, using these weapons depends on the situation.

Regarding Hezbollah’s tunnel network, Daoud mentioned that while there isn’t exact information, it is believed that the area from the border to seven kilometers inside Lebanon is likely covered by an underground tunnel system.

This is why Israel wants Hezbollah pushed beyond the Litani River, as it thinks there are no tunnels beyond that point. However, Daoud emphasized that these are only estimates, and no one has confirmed information.

Israeli studies suggest that Hezbollah has built a complex underground tunnel network in Lebanon, stretching for several kilometers.

These reports highlight how Hezbollah benefits from Lebanon’s natural landscape, which makes tunneling easier. Modern tunneling equipment is expensive and not widely available, even to the Lebanese government, with some tunnels taking years to complete.

Dr. Tony Nemer, a geology and seismology expert at the American University of Beirut, explained that Lebanon's rocks are mainly limestone.

When exposed to water containing carbon dioxide, the rocks form carbonic acid, which can hollow out the limestone. This natural process has led to the formation of many caves in Lebanon.

Nemer pointed out that the karstic nature of these rocks makes digging tunnels easier.

He noted that while most of Lebanon’s rocks are limestone, there are also some sandy and volcanic rocks, but these make up only 15%-20% of the country’s terrain.



Lebanese Front’s Tunnels Used for Defense, Attack and Launching Missiles

In 2019, Israeli forces searched for attack tunnels dug in southern Lebanon that extend into Israel (Israeli Ministry of Defense)
In 2019, Israeli forces searched for attack tunnels dug in southern Lebanon that extend into Israel (Israeli Ministry of Defense)
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Lebanese Front’s Tunnels Used for Defense, Attack and Launching Missiles

In 2019, Israeli forces searched for attack tunnels dug in southern Lebanon that extend into Israel (Israeli Ministry of Defense)
In 2019, Israeli forces searched for attack tunnels dug in southern Lebanon that extend into Israel (Israeli Ministry of Defense)

Lebanon’s Iran-backed Hezbollah group faces Israeli air superiority and technological capabilities by going underground. The group has built a massive and complex network of tunnels in the South, the southern suburbs of Beirut, and the Bekaa regions.
The ongoing clashes between Hezbollah and the Israeli army on the southern Lebanese border, which erupted in October, has brought back the spotlight on these tunnels, which have been shown to be divided into 3 types.
The first are defensive tunnels that allow the party’s fighters to take shelter from aircraft raids. The second are offensive tunnels that the Israeli army said it destroyed in 2019, and the third group consists of small tunnels to hide rocket launchers and which appeared in one of the video clips broadcast by Hezbollah’s military media last month.
According to Israeli reports, Hezbollah started digging tunnels in the 1980s and 1990s, but those remained far from the border with Israel. However, in 2006, the Israeli media showed a tunnel that the Israeli army discovered during the July war inside Lebanese territory, and quoted officials as saying that the party’s construction of cross-border tunnels began before the start of the Second Lebanon War in 2006.
Concerned about tunnels extending into Israeli territory, Israeli authorities launched a campaign in 2018 to destroy this infrastructure, and announced in 2019, the end of its operation to raze all of Hezbollah’s cross-border attack tunnels.
The last tunnel that Israel destroyed stretched along 800 meters. The Israeli army said the tunnel extended over dozens of meters into Israel, and was dug to a depth of 55 meters, making it the deepest tunnel discovered by the army. The tunnel was equipped with electricity, had a railway to transport equipment and waste, exit stairs and other elements that made it more advanced than other passageways that were uncovered.
In 2020, the Israeli Ministry of Foreign Affairs, with the participation of the Israeli army, organized a field tour for 12 diplomats from UN Security Council member states, to show them the tunnel on the northern border with Lebanon.
Since the eruption of war on Oct. 8, Lebanese sources have confirmed that the Israeli army used bunker-piercing bombs to destroy tunnels suspected of being built by the party in the border area.
A report issued by the Alma-Israel Research Center said that after the 2006 Lebanon War, the party established a defensive plan to confront any possible Israeli invasion, with dozens of operations centers equipped with local underground networks and tunnels.
In addition to the previous two types of tunnels, Hezbollah media revealed a third category. Last month, the party’s media presented a report on the party’s artillery and weapons, and one of the clips showed a rocket launcher rising from the ground and launching a missile, indicating that the party hides these platforms underground.