The Rogues' Castle is a fortress located in the deep Wilderness, specifically in levels 50-54. As with all of the land beyond the long fence or border, this area is only accessible to pay-to-play players. It is inhabited by Rogues, Rogue Enforcers, and Rogue Captains who can be attacked and auto-pickpocketed. An aggressive boss monster, the Chaos Elemental, can be found lurking around or inside the castle. The song Regal is unlocked near the castle. It is also known as "castle in the dark land" when trying to obtain the ghostly cloak. The main door remains locked at all times, and one of the side doors must be used to enter the castle.
- There are four floors in the castle, the upper two being towers.
- There is a range on the ground floor.
- Several gold ore respawns are spread throughout the inside of the castle (three on ground floor and one on the first and third floors).
- There are three chests on the first floor that can be thieved from with a lockpick.
- There is a bronze sq shield spawn on the first floor and an iron dagger spawn on the third floor.
- Two cape merchants walk around the area.
The Chaos Elemental patrols the west and south perimeter of the Rogue's Castle and can attack players "offscreen", making the area quite dangerous to reach. However, there is a Teleportation obelisk in the area, which makes for a fast transport to the castle area, or a quick escape for players being hunted by the Elemental. The Elemental does not enter far into the courtyard of the castle but can attack quite far from just inside the southern gate. Prior to the Elemental's release the castle was actually one of the safest areas in the Wilderness.
Players come here mainly to kill the Chaos elemental. Some players come here to pickpocket the Rogues for the Thieving experience (although the risk of death being high makes players being sighted rare). Players also come here to rescue the Rogue (Varrock) from the castle. The castle is used as part of The Curse of Zaros and Lost Her Marbles miniquests. Furthermore, it is the location of a Treasure Trail Coordinates clue. Other than that, it has no quest purposes.
Just north of the Rogues' Castle, there exists a deposit of basalt along the shore, and are only found in two locations in the game, the other being near the Lighthouse. The meaning of these blocks is unknown.
- When the Wilderness was updated, people were getting stuck in the jail, so a portal was placed to allow them to get out.
- The hexagonal blocks found north of the castle closely resemble the basalt formations of the Giant's Causeway in Northern Ireland, which were formed through volcanic activity around 40 million years ago.