Heading clockwise from the northernmost point on the route, Route 126 proceeds east, meeting the southern terminus of Route 124 after a short distance. Southeast of this point, the route intersects a channel that leads to Route 127. Directly west of the middle of the channel is a Swimmer, one of three on the route. To the southwest, near the base of the volcano, is the second Swimmer. The third Swimmer is in the westernmost area of the route, accessible only by utilizing the network of underwater pathways.
Unlike Route 124, which had only small pools of deep water scattered throughout the route, most of Route 126 is deep enough to Dive into, including the area surrounding the volcano base. On the ocean floor, Trainers can pass through seaweed to catch wild Pokémon as well as enter Sootopolis City, the entrance of which is located on the southern side of the volcano on the ocean floor.
All items on Route 126 can only be accessed with the use of Surf.
In the northern area—accessed by using the northern Dive spot in the main underwater area and then using the next Dive spot to the north to return underwater—in the western end of the area, two tiles away from the south wall and approximately midway between the walls to either side (hidden)
In the northern area—accessed by using the northern Dive spot in the main underwater area and then using the next Dive spot to the north to return underwater—in the middle of the easternmost bare patch of seafloor among the seaweed (hidden)
In the main area, to the southwest of the north Dive spot, approximately three tiles away from the west wall of the dead end and one tile south of the level of the south wall of the corridor leading into the dead end (hidden)