The Vermillion Dome of Doom is a large structure located in the Vermillion Swamps. It serves as the headquarters of Krux and Acronix, and it is also where the Iron Doom super-weapon was constructed by the Vermillion. The entire structure resembles a giant Vermillion egg.
After the Ninja discover Dr. Saunders' true identity as Krux, the Time Twins and their Vermillion troops were forced to relocate from Krux's lab at the Ninjago Museum of History to the Vermillion Swamps. There, Krux and Acronix create a large headquarters for them and their troops, as well as a staging ground for the Iron Doom's construction.
In the Swamplands, Krux and Acronix built their new headquarters: The Vermillion Dome of Doom. The massive egg-shaped silo stands at the epicenter of the Vermillion camp and is surrounded by barracks, mess hall, prison center and armory production. The Dome also housed the Iron Doom before it disappeared in time.