Magnus builds his laboratory in The Colossus

Construction beginning/end

Magnus builds his laboratory under The Colossus and trains the Gerudo in various dark arts.

In Gerudo desert, there are five temples dedicated to the Gerudo gods.Three of the five are dedicated to two gods, one (The Colossus) is dedicated to the first (the god of spirit, Damare), and one is dedicated to the eighth (the god of warmth, Vile).   Magnus builds a laboratory beneath the Colossus. However, he refuses to let even Damare and her Champion know how to enter it.   He also has Runis guarding the lab, preventing any wanderers from going into his section. Runis actually seals up the lab every time Magnus enters/exits.   Magnus teaches the gods and champions many dark arts in the Colossus. However, Vile and Vile's champion are the only ones who actually show significant interest. They visit Magnus often, and Magnus often visits their temple in the Highlands.