History
Hell's Heaven was a secret Hydra base used for bioweapons research, mostly involving the hive symbiotes.
The base was attacked by a combination of Nick Fury's Team Black and the Howling Commandos PMC, whom were using two ex-S.H.I.E.L.D. Helicarriers that they stole from H.A.M.M.E.R.. It was a fierce battle as the base was heavily fortified and armed, including with several squadrons of dreadnoughts (airships).
When they got inside, they found a room where Hydra was turning the unfortunate test subjects into Hive symbiotes. They blew it up and then headed out of Chinese airspace on the two Helicarriers. Before they made it out of China, both of the Helicarriers were intercepted by a squadron of dreadnoughts commanded by the Gorgon. Which shot down both of the Helicarriers, while losing several dreadnoughts.
The Helicarrier crews bailed out and the survivors then engaged in a brutal battle with Hydra troops landed by the dreadnoughts and backed by hovering gun platforms. The Caterpillars and Howling Commandos PMC were nearly annihilated, with only a few survivors. In the aftermath of the battle, the Chinese military moved in, and arrested the survivors. They also confiscated the equipment, including the crashed helicarriers, thereby giving them the ability to reverse engineer the technology.[1]Notes
- It is unknown if there is any connection between Hell's Heaven and Heaven's Hell.