The 1st Floor (第1層, Dai 1-sō?) of Aincrad is geographically the largest floor. It is almost completely circular with a diameter of 10 kilometers (80 square kilometers). The 1st Floor is roughly the same size as Saitama Prefacture Kawagoe City (population 330,000).The main settlement on the 1st Floor is the Starting City, but there are also numerous other towns and villages on this floor.

The 2nd Floor (第2層, Dai 2-sō?) of Aincrad is a savanna realm covered in plains and boulders and roughly the same size as the first floor.The background music for the second floor is more sorrowful in tone (oboe music) than the string orchestral music for the first floor. The NPCs also have subtle differences in their garments.

Unlike the woods Horunka on the 1st Floor or the southern area of the 2nd Floor, the 3rd Floor is covered entirely by enormous ancient trees. The southern area of the floor is called the Forest of Wavering Mists, a baffling place choked with thick fog. The labyrinth is located in the northern area of the floor, which is separated from the southern area by mountains, with a tiny pass guarded by the Field Boss.