Incredibly tall rocket

When the Decepticons detected a mysterious energy source in a crevice in the rocky, mountainous desert, they parked an incredibly tall rocket among the peaks at an edge of the crevice, where it is used as a temporary base of operations. The rocket is camouflaged to resemble an absurdly steep mountain and for one reason or another, its disguise as a part of the mountain is not limited to its exterior. At least half the interior is designed to resemble a cavern.

The Transformers cartoon
When a large collection of korlonium crystals was found, Megatron had the rocket parked nearby for his latest plan to destroy the Autobots. He had his troops under command of Starscream await the Autobots near the crystal site and attack them, intending to use the battle as a distraction. Laserbeak was sent out to get Optimus Prime away from the others, knock him out and collect the data Megatron needed to feed his cloning device. Laserbeak's mission met with success and the machine created a flawless copy of the Autobot leader.

Infiltrating the clone into the Autobot army, Megatron tried to gain access to Teletraan I, but failed to do so before the real Optimus Prime showed up. With the Autobots unwilling to just kill the other Optimus, Megatron had the rocket's systems send out a signal that tricked Teletraan I into believing the korlonium crystals were becoming unstable and liable to explode. When the Autobots went to look, they stumbled into a second ambush. As before, Megatron supervised his troops from the rocket base, this time in the company of Starscream. The Decepticon leader revealed to his second-in-command that he intended to have him killed by the Optimus Prime clone to convince the Autobots the clone was the real deal, upon which news Starscream fled the base. Megatron sent Laserbeak to bring him back. At the time, Windcharger and Spike were near the rocket and saw the two Decepticons fly out off it, clueing them in on the rock formation's true nature. When Laserbeak returned with Starscream, the two sneaked after them into the rocket, where they overheard Megatron elaborate he intended the Optimus Prime clone to kill a clone of Starscream. After also hearing about the danger the korlonium crystals posed and seeing the Starscream clone made, Spike and Windcharger followed the dispatched clone to get back outside, but Laserbeak had spotted them. Spike was captured and though Windcharger escaped, his speed made him fall from the rocket's exit into the korlonium crystal field below.

The Decepticons opted to spare Spike for as long as it would take them to get him footage of the Autobots' destruction. That moment got close, but just as the Optimus Prime clone had convinced the Autobots he was the real one and prepared to lead them into the korlonium crystal crevice, Windcharger turned up alive and revealed the truth about the Optimus Prime clone. When the real Optimus Prime subsequently led the Autobots to storm the rocket and free Spike, it was launched into the sky before the Autobots could reach it. As a parting gift, Megatron did see fit to toss Spike out the window.