On the last Saturday in September as part of the World’s Largest Ghost Hunt, National Ghost Hunting Day kicks off an annual international investigation of the paranormal.

Seeking paranormal activity isn’t limited to crumbling ruins and darkened, forgotten corners of the world. Both Ann Bolyen’s ghost in the Tower of London and several haunted spaces in the White House in Washington, D.C. are two very public and populated places which come to mind. Enthusiasts bring attention to historical properties and have an interest in preservation as well. From Civil War-era towns like Old Salt Sulphur Springs in Virgina to ghost walks in old opera houses like Rohs Opera House in Kentucky and train-loving ghosts in Colorado, many locations are ready for sleuthing on National Ghost Hunting Day.