The Great Archive of Labyrinthia is a location in Professor Layton vs. Phoenix Wright: Ace Attorney. It is managed by Ridelle Mystere. Professor Layton and Luke visit the library to get the "Grand Grimoire".
The library has a secret basement, which contains information about the attack of Great Witch Bezella on Labyrinthia roughly 10 years ago. Clues to find its entrance are hidden in the "Grand Grimoire".