This is one of the most mysterious places in Morocco discovered by chance in 1916. That year, a shopkeeper who wanted to expand his shop discovered an underground gallery of 1100 m². According to historians, this space was built in 1514 by the Portuguese and would have served as an arsenal or store before being refitted in tank. Of Gothic architecture, this room is supported by five rows of columns and vaults, with in the center, a skylight. For the anecdote, know that this piece served as a backdrop to several films including "Othello" by Orson Welles.