Fortress of the Fallen

The Fortress of the Fallen is The Fallen Empire's headquarters, hidden within an unknown location.

History
Shadowmaster constructed the Fortress of the Fallen after his defeat by Korasak, in an empty dimension. He resided in this fortress for most of his time, carving his plan in stone. After some time, Shale found the establishment, and took residence in it, founding the Fallen Empire.

As the Fallen Empire grew, so did the fortress, and it eventually became their official headquarters. Shadowmaster eventually summoned 8 beings of different universes to the fortress, forcing them to fight in order to produce chronium deposits (from universal distortions).

Later, Shadowmaster discovered the mountain in which the Golden Lord resided in. After defeating him, he teleported his fortress onto the top of the mountain. The fortress was invaded by the Golden Lord's team of heroes later, and was partially destroyed. Shadowmaster relocated the fortress to another universe after this.

In the new universe, Shadowmaster constructed a massive virtual arena above his fortress, sending the rebels inside to kill them. The outcome is currently unknown, but the fortress was relocated to the empty dimension again after this.

Shadowmaster built a replica of the fortress on the Northern Continent much later, enlisting a team of Shadow Toa to protect it. The fortress was invaded by Serrakaan, who killed the 10 Toa, and arrived to kill Shadowmaster. Shadowmaster threatened to expose Serrakaan as a fraud Makuta before framing him for the deaths of Matoran and Toa as Ra arrived. The fortress was destroyed by an avalanche in the battle between Serrakaan and Ra.

After Shadowmaster's body was destroyed, he relocated the fortress to an unknown location on Spherus Magna.

Features
The Fortress of the Fallen is built of an unknown, black rock, reinforced with protosteel and exsidian. The fortress is cloaked in a dark force field.

Exterior
The Fortress extends several thousand feet in the air. The courtyard is grassy and cold, and the main gate is shaped in the likeness of Shadowmaster's face. The courtyard is lined with ancient statues aligned in a pattern, alternating between statues of Shadowmaster, Asgard, and Serrakaan.

Interior
The Fortress holds a great number of chambers, only a small number of which have actually been seen by those other than Shadowmaster himself.
 * Entrance Halls - The Entrance Halls are several long, straight corridors with blood-red curtains and ancient, lettered (Matoran letters) tiles lining the walls, ceiling, and floor.
 * Central Courtyard - The central courtyard is connected to the entrance halls, resembling the outside courtyard. The chamber has a ceiling that opens and closes upon Shadowmaster's whim. The walls are lined with bookcases, one of which hides Shadowmaster's library. The walls, floor, and ceiling are covered with moss.
 * Personal Chambers - The personal chambers are rooms belonging to the individual members of the Fallen Empire. Each chamber contains a cold, rock bed, and a small, personal armory, as well as a window. Any other modifications are forbidden.
 * Library - A large, secret chamber hidden behind a bookcase in the central courtyard.