Hezbollah maintains a major underground military facility in Lebanon’s northern Bekaa Valley near the Syrian border; a site that Lebanese security sources describe as one of the group’s most important remaining strategic assets away from the immediate southern front.

A Lebanese security source told Erem News that the facility is far more than an arms depot or a network of tactical tunnels. It is described as a large underground military complex whose importance has grown during the current war, particularly as Hezbollah has suffered damage to parts of its military infrastructure in southern Lebanon and the Bekaa and lost much of the freedom it once enjoyed to use Syria as a supply corridor.

The source did not disclose the facility's precise location. But information published over the past decade points to the Hermel area in the far northern Bekaa, where Israeli and Western reporting has identified a deep network of Hezbollah military infrastructure, including missile facilities, strategic tunnels, storage sites and training areas linked to the Syrian border.

One of the earliest significant reports emerged in July 2017, when French intelligence publication Intelligence Online reported that Iran and Hezbollah were working on an underground missile-production facility near Hermel that was intended to manufacture Fateh-110 medium-range missiles.

Reports at the time referred to two underground facilities — one in the Hermel area and another in southern Lebanon between Sidon and Tyre. The Israeli Alma research center later cited the Hermel facility, describing it as part of an Iranian-backed effort to develop Hezbollah's capacity to manufacture missiles inside Lebanon.

In October 2024, Israel said it had struck underground infrastructure belonging to Hezbollah's Unit 4400 in northeastern Lebanon. Israel described a tunnel about three kilometers long that linked Syria and Lebanon and said the network had been used to smuggle Iranian weapons into Lebanon.

That information is consistent with the broader picture of a Hezbollah infrastructure extending beneath the mountainous border region, although it does not by itself establish that the tunnel is part of the specific facility described by the Lebanese source.

The Alma Center, which tracks Hezbollah's military infrastructure, has described the group's tunnel network as a large project built over decades, comprising strategic and tactical tunnels as well as routes used for movement and smuggling.

The picture that emerges is therefore potentially broader than that of a single underground installation. The facility described by Erem News could form part of an interconnected network beneath the Bekaa mountains, combining storage, command, logistics and potentially missile-related functions.

The Qusayr area in Syria and the route toward northern Hermel have long been identified as an important axis for the movement of weapons into Lebanon.

That route has become more significant — and more vulnerable — as Hezbollah's ability to rely on Syrian territory as a secure supply corridor has diminished.

The Lebanese source stressed that the facility should not be confused with the underground complex at Janta, near the Syrian border.

Israel said in November 2024 that it had struck a large underground Hezbollah facility in Janta that was linked to the production of precision-guided missiles.

The source said the facility in question is a separate and still important Hezbollah asset.

The wider Hermel area has repeatedly come under Israeli attack. In September 2025, Israel said it had carried out 12 strikes against Hezbollah military compounds in the region, which it said included Radwan Force training camps, weapons depots and facilities used to train fighters.

The source said there was no clear evidence that the facility belonged organizationally to Hezbollah's Badr Unit, whose principal operational role has traditionally been associated with the southern front.

The Radwan Force, Hezbollah's elite fighting formation, has a documented presence in the northern Bekaa, but that does not necessarily mean the facility is controlled by the unit.

Instead, the source believes the site is more likely to be a central strategic asset used by several Hezbollah formations, while Unit 4400 handles part of the logistics network connecting the group to the Syrian border.

Unit 4400 has been described by Israel as responsible for transporting and smuggling Iranian weapons into Lebanon. The Israeli military's account of the northeastern Lebanon tunnel in October 2024 similarly linked the infrastructure to the unit. 

The distinction has become particularly important during the current war as Hezbollah has moved fighters between its rear areas and the southern front.

Reuters reported during the 2024 conflict that Hezbollah's extensive underground infrastructure and dispersed command structure helped the group withstand heavy Israeli strikes. The report also said the group continued to move weapons and redeploy fighters despite the Israeli campaign. 

The Bekaa, in that context, can serve not simply as a place to store weapons but as a strategic rear area from which Hezbollah can regenerate its forces and replenish the front.

Lebanese political researcher Ali Hamadeh told Erem News that the importance of the northern facility lies partly in the different role it plays from the underground complex beneath Ali al-Taher Hill in southern Lebanon.

He said Hezbollah had spent years developing a geographically dispersed military architecture so that the destruction of one command center or facility would not bring down the broader network.

The facilities in the Bekaa near Syria have particular strategic value because they were historically connected to Iran's supply route through Syrian territory, Hamadeh said.

They also provided Hezbollah with strategic depth far from the Israeli border, allowing it to store weapons, accommodate military units and command centers and replenish the southern front when necessary.

The war has placed those facilities under unprecedented pressure, he said, as Hezbollah's ability to move through Syria has narrowed and supply routes and weapons depots have come under repeated attack.