Write about a group of friends who stumble upon a mysterious key while hiking in the mountains

Write about a group of friends who stumble upon a mysterious key while hiking in the mountains. The key unlocks a hidden door in the side of a cliff, leading them to a forgotten underground chamber filled with ancient treasures and secrets. But as they explore further, they realize they are not alone in the chamber and must confront a sinister force that has been guarding the riches for centuries.