Few horror movie scenes are as memorable as the moment when the Blob attacked a movie theater in the 1958 film that bears the alien monster’s name. In that moment, to real moviegoers in theaters all across the country, it seemed like the very space they were sitting in could be attacked at any moment and that they themselves might be the victims. And today, once every summer, audiences can relive that moment in the very theater where the infamous scene was shot.

The Colonial Theatre in Phoenixville, Pennsylvania, where the iconic scene was filmed, was built in 1903 when the surrounding city was a growing industrial town. The owner converted a pair of existing storefronts into a show space that was unlike anything around for miles. The grand theater hosted vaudeville shows, musicals, silent movies, and more, becoming a fixture in the local landscape. As entertainment evolved, the theater became more of a movie palace, but stuck to its roots with pre-show music that was performed on a large pipe organ.

When the filming of The Blob began in and around Phoenixville in 1958, the Colonial, with its elaborate marquee, was chosen as the perfect location for an attack. In the film, the monster infiltrates a packed house of moviegoers, rushing them out the doors in a mad mob as they try to escape the creature. Once it leaves, the Blob strikes a sort of “hero shot” in front of the theater, inducting the movie house forever into the annals of famous horror movie locations.

The Colonial continued to operate after the movie was filmed and is still there today, run by a nonprofit group operating the historic space as a cultural arts center. It has finally embraced its beastly heritage with a three-day weekend Blobfest every summer which sees replicas of the infamous creature appear around town and the marquee restored to how it looks in the film, complete with a banner advertising the theater as being “Healthfully Air Conditioned.” Blobfest usually includes a screening of the classic movie on Saturday and Sunday, with wild applause when the Colonial makes its appearance. But the biggest thrill is reserved for Friday night when fans can purchase tickets to participate in an actual reenactment of the moment when the Blob attacks the theater and the panicked audience stampedes out the front doors into the street beyond.