Despite the use of the word "upper", these floors are the easiest to navigate and produce the weakest monsters, as they are closest to the surface. The upper floors change from blue to green colored walls and are decorated with phosphorescence stones that emit light.

The middle floors are known as a cave labyrinth. Jagged rocks and sheer cliffs make up the interior of the dangerous changing maze. Starting from the 16th Floor the walls, ground, and ceiling become rocky. The light becomes dim and the rocky hallways become hard to walk through. A huge wall appears in the big room located called the Big Wall of Grief, on the 18th floor; The wall spawns the Monster Rex Goliath.

The 25th Floor marks the beginning of the Great Fall, a huge waterfall estimated to be 400 meters wide and twice that in length, which lasts until the 27th Floor. The 25th Floor was also described as being a paradise of water. In order to move on to the next floor, adventurers must navigate through a series of passageways varying in elevation around the waterfall to reach the passageway at the bottom of their current floor. The bottom of the waterfall basin on the 27th Floor leads out to Melen's Lolog Lake, though it's unknown where the water goes now due to the exit being sealed using the Leviathan's remains. The Monster Rex Amphisbaena is located here and can freely move between the floors and the labyrinth area.

The 37th Floor is known as the White Palace as the walls, ground, and ceiling are colored white with the floor being a giant labyrinth. The entrance to the 38th Floor is located at the center of the floor, which is where the Monster Rex Udaeus is located, and around it are five huge circular walls that adventurers have to navigate through to reach the center. Below the lower floors change drastically by level, climate, terrain and atmosphere.