If this installation becomes a regular component of operations by the Islamic Republic of Iran Air Force, or IRIAF, it should provide a useful additional layer of protection against some forms of aerial attack. In doing this, Iran will follow the lead established by several other countries, including China, North Korea, Switzerland, and Taiwan. The disclosure also comes hot on the heels of the biggest joint U.S.-Israeli military exercise in history, which took place in January and that you can read more about here.

A series of photos and videos released today by Iran shows what it describes as a new underground airbase, named Eagle 44, during a visit by Iran’s Army chief, Major General Abdolrahim Mousavi, and Iranian Armed Forces Chief of Staff, Major General Mohammad Bagheri. It’s not immediately clear if this is really an all-new facility that’s been dug out of a mountain range or if it is an adaptation of one of the various underground bases we’ve seen in the past, used for storing and protecting missiles and drones, for example.

Whether an entirely new project or not, work on the underlying facility would have to have been started some time ago, considering how long it takes to build these kinds of facilities. What’s obvious, though, is that it’s large enough to accommodate fighter jets, with photos showing several fully armed F-4s within the base.