A video of the new, underground facility is included in the link.

Snip:

Chief of Staff of the Iranian Armed Forces Major General Ali Abdollahi has warned the enemies that surprises will emerge one after another in any potential future war.

General Abdollahi issued the warning during the unveiling ceremony of a new missile city belonging to the Aerospace Force on Tuesday.

[…]

The newly unveiled facility offers a glimpse into another part of the missile infrastructure of the IRGC Aerospace Force, which supports the operational capabilities of missile units and helps maintain their readiness to counter potential threats.