Decepticon Headquarters (G1 Cybertron)
Decepticon Headquarters is a Cybertronian structure that serves as the primary base of operations for the Decepticons on Earth. Across various continuities, these buildings have taken a wide range of shapes, sizes, and locations.
Often they is not referred to by any proper name beyond a generic descriptor such as "our base".
Marvel Comics
Decepticon Fortress
See separate article.
Club Con
See separate article.
New Jersey base

Scorponok established this base; it was located in the meadowland swamps of northeastern New Jersey, within sight of the Midtown Manhattan skyline. The move was prompted by a plan to channel storm energy through the Empire State Building in nearby New York City. The plan failed, but the Decepticons did not bother to relocate.
This base was severely damaged when Shockwave and Starscream made their bid to overthrow Scorponok as Decepticon leader. It was presumably left abandoned as all the Transformers on Earth were teleported to Cybertron shortly thereafter.
Generation 1 Cartoon
Decepticon Headquarters
After their second space cruiser crased to the bottom of the ocean, the Decepticons simply built a new headquarters around it. This complex of buildings would serve as their base of operations for years to come.
Notable features of the base included a giant telescoping elevator that rose above the surface of the ocean, allowing the Decepticons to enter and leave at will.
Flooding was, naturally enough, a recurring problem for the undersea base. Decepticon Headquarters had to be partially or fully drained of water on at least four separate occasions.
Giant Decepticon Symbol
Ever the masters of stealth and subtlety, the Decepticons created a temporary base in the desert in the shape of an enormous Decepticon symbol.
They used it to manufacture toasters.
Incredibly Tall Rocket
The Decepticons used a rocket ship as another temporary base, camoflagued to resemble an absurdly steep mountain. It was here that Megatron created a perfect clone of Optimus Prime.

