Witchers' Laboratory
From Witcher Wiki
The famous witcher laboratory holds the most closely guarded secrets of the castle - mutagenic plants, hallucinogenic mushrooms, natural stimulants and potion ingredients. It is here that young apprentices were subjected to the incredibly painful Trial of the grasses, which only a few survived, gaining superhuman abilities in return.
It is this laboratory which is pillaged in the Prologue of the game. Leo meets his end at the hands of the Professor and Triss Merigold is nearly killed defending it.
