Darkmount (Earth)

Darkmount is a massive, 5.5 mile high fortress situated near Jasper, Nevada. Forbidding and evil, it is armed with multiple fusion cannons, making it the perfect foothold for Megatron's future conquest of Earth. It's also sometimes called New Kaon.

Prime cartoon
After activating the Omega Lock, Megatron directed a shaft of energy through a space bridge, striking Earth near Jasper and creating a huge Cybertronian fortress. Agent Fowler had the town evacuated as a result. When the Decepticons returned to Earth, Megatron dubbed this fortress New Kaon before proceeding to destroy the nearby Autobot base.

When human military forces moved in, Megatron used the fortress's fusion cannons to devastate both them and most of Jasper. He had also by that time decided to call the fortress Darkmount. The Decepticons moved in shortly afterward.

Smokescreen infiltrated the base using the phase shifter in an attempt to find the Forge of Solus Prime, which turned out to be stored in the Nemesis.

Once he arrived on Earth and learned of the situation, Ultra Magnus planned a mission to neutralize Darkmount in tandem with Earth's military. Despite drawing off a large portion of the Decepticon forces, the remnants of Team Prime were eventually overwhelmed. Fortunately, the timely arrival of Optimus Prime, recently upgraded, allowed them to turn the tide and disable the fusion cannons, allowing Fowler and his fighter squadron to bring the citadel down.