The stone is guarded by a series of obstacles and creatures:
* The three-headed dog Fluffy: This massive creature guards the first entrance to the Philosopher's Stone's chamber.
* The Devil's Snare: This dangerous plant is the second obstacle.
* The Flying Keys: These enchanted keys are the third challenge, requiring quick reflexes to avoid them.
* The giant chessboard: This life-size game of chess is the fourth obstacle, requiring strategic thinking and a knowledge of chess.
* The potions puzzle: This puzzle tests one's knowledge of potions.
* The mirror of Erised: This magical mirror reflects one's deepest desire.
It's important to note that Professor Quirrell, possessed by Lord Voldemort, is also considered a guardian, as he is attempting to steal the stone himself.
Overall, the Philosopher's Stone is heavily guarded by a series of magical challenges designed to test the courage, wit, and skills of anyone trying to reach it.