The Slayerdungeon of Prifddinas is a high-level dungeon located underneath the city of Prifddinas. The dungeon also contains the highest level Slayer Master and the Slayer Grandmaster, Sarixs. In order to get tasks from him, you need a Slayer level of 90, and a combat level of 125. There are no requirements for entering the dungeon itself, but it is heavily adviced that anyone who enters the dungeon has higher combat level than 100, otherwise you are likely to die very quickly in the dungeon. The dungeon is famous for the Crystal dragon and Rho'mox the Toxic.