The Reaper Fortress is the supposed home of the Reapers, introduced in Kid Icarus: Uprising. It is a massive castle made completely out of rock and bone, built within a deep, foggy ravine. Both the fortress and the ravine are infested with many of Medusa's underworld monsters, as well as numerous traps. The fortress is also home to an arena where the boss form of the Reaper is fought. The Reaper Fortress is the central location of a chapter in the storyline of Uprising, known as The Reaper's Line of Sight.
The path to the Reaper Fortress has Pit traveling through a long ravine filled with enemy soldiers sent by Medusa. The Reaper itself also patrols the ravine's corridors using its line of sight, which takes the form of a red beam. If Pit flies through the beam, the Reaper will summon up to three Reapettes to give chase. Aside from these primary enemies, the ravine itself is also littered with numerous obstacles and traps, such as jagged walls, heavy wind currents, and clashing stone surfaces that close in on Pit as he tries to fly through. The ravine is also maze-like in structure, even confusing Palutena as she was attempting to lead Pit through the area.
The Reaper Fortress lies within an enormous canyon at the end of a very narrow tunnel. The structure's many towers are heavily armed with numerous turrents that launch red lasers at Pit as he approaches. By dodging these lasers, Pit is forced to enter the fortress itself straight through the front gate. The inside of the fortress is where Pit's ground mission takes place. Like the ravine, the Reaper Fortress is filled to the brim with both enemies and traps, including spikes that suddenly jut out of the ground when approached and spinning blade mechanisms that follow a set path. At the end of the fortress is a large arena where the Great Reaper will be fought.
The Reaper Fortess is notable for being made almost completely out of bones, or at least sculptures that resemble bones. The main building itself is lined with animal skulls and massive, tusk-like structures that curve around the entire fortress. There are also two curving lines of pillars holding up what look like large vertebrae. These structures also support two towers standing on each side of a small bridge that leads straight to the entrance of the fortress. The main building, the pillars, and the towers are all lined with dangerous laser turrets.
In the center of Reaper Valley sits this terrifying home of the Reapers and their leader, Great Reaper. Intended to be a central hub for spirits traveling to the Underworld, it has become a buffet of literal soul food for the hungry villain.
- The music that plays inside the Reaper Fortress is a remixed version of the theme that played whenever the Reaper spotted Pit in the original Kid Icarus.
- The artwork showing the interior of the location appears to depict Dark Pit, but he doesn't actually appear at all in this level in the game.