The Pest Control Islands are a number of tropical islands found in the Southern Sea that serve as the battlegrounds in which the Pest Control minigame takes place. They are the southernmost known point of Gielinor and can be accessed by the boats at Void Knights' Outpost.
The islands were at one point in control of the goddess Marimbo, likely due to their close proximity to Ape Atoll, but they were abandoned. They were then rediscovered by the mad wizard Melville Grayzag in 149 of the Fifth Age and he began opening portals that spawned many void pests on the islands, which lead to the arrival of the Void Knights. During the Pest Control minigame, players are tasked with destroying all the pest portals around the edge of an island while protecting a Void Knight in the centre of the arena in an attempt to stop the pests from claiming the island.
Each island has a large stone podium in the centre, surrounded by battlements made of wood and stone; with three different gates which can be used to access the edge of the island. Four towers can also be found dotted around the walls, which can be used to range or mage pests from above. A beach can be found to the north of the islands, which is where the Void Knight lander lands, and where players spawn during the Pest Control minigame. Piles of logs can also be found scattered across the beaches, which can be used to repair various defences on the islands.
Outside of the fort, large cliffs surrounded by reeds can be found around all other edges of the islands, preventing access to their beaches. Large stone doorways decorated with murals can be found in the cliffs, and small stone thrones can be found just next to the southern cliffs, both of which possess architecture similar to that found in the Cabbage Facepunch Bonanza arena. Four portals are dotted between the cliffs and the battlements, which is where the pests spawn.