The Fall of Gondolin is a significant event in J.R.R. Tolkien's legendarium, particularly in the history of Middle-earth. It describes the tragic downfall of the hidden city of Gondolin, which was founded by the Elven king Turgon. The city was eventually betrayed by the dark lord Morgoth, leading to a devastating attack by his forces, including dragons and balrogs. The story follows the heroics of characters like Tuor and Idril, who attempt to save their people from destruction. Despite their efforts, Gondolin falls, marking a pivotal moment in the struggle between the forces of good and evil in Tolkien's world.