The Dorgesh-Kaan South Dungeon is a dungeon south of the underground city of Dorgesh-Kaan, beneath the Dorgesh-Kaan agility course. Entry to the dungeon requires completion of the Death to the Dorgeshuun quest and a rope to get down. The dungeon is dark and requires the player to have a light source or face relentless damage from stinging insects. A tinderbox is recommended (to relight the light source, just in case) but is not necessary. An Antipoison potion may also be helpful, as there are several poisonous creatures in the dungeon. The area was released on 20 March 2007.
- There is a two-way passage between the dungeon and the Kalphite Lair.
- Fairy ring A•J•Q provides access between the dungeon and Zanaris, for players who can use the fairy rings.
- A ladder to the agility course and to Dorgesh-Kaan city is in the north.
- There are two net fishing locations for frog spawn
- Molanisk - only found in this dungeon.
- Cave Bug - two types; levels 12 and 8. Both versions require level 7 Slayer to kill.
- Big Frog
- Giant Frog
- Cave Crawler - Highly poisonous (starting at 80); requires level 10 slayer to kill.
- Cave Slime - Poisonous (starting at 30); requires level 17 slayer to kill.
- Rockslug - requires level 20 slayer and Bag of salt to kill.
- Turgall (above in the electricity plant by the agility course).
- Movario (before and during While Guthix Sleeps quest).
- Darve (before and during While Guthix Sleeps quest).
- Elite Khazard guard (during While Guthix Sleeps quest).
- The Land of the Goblins quest contains a part involved with this dungeon.
- The Chosen Commander quest also uses this dungeon briefly on two occasions.
- When the player asks Turgall how the power station works, he replies "By magic!" and then proceeds to give an accurate description of a modern-day geothermal power station, substituting the words magnetic, electric, and electricity with magic or magical.