The Queen of Angels Hospital, located somewhere on Vermont Ave. is believed to be the source of strange supernatural activity. The Queen of Angels is a well known filming location in Hollywood and is used frequently in movies and TV shows. It's not so much the whole building that's haunted but one of the floors. Possibly the 9th? Maybe, not sure. Security guards in the building have told of periodic motion detector alerts specifically from that floor and chairs spinning in the center of the floor without stopping.
There is also a small rumor that the 1995 film, The Prophecy, was filmed in this hospital. During shooting, Christopher Walken was said to have visited the "Haunted floor" and purportedly had an encounter with the spirit in question. (If anyone can corroborate this rumor it would be greatly appreciated as just by looking at the 'filming locations' in IMDB.com for this film I don't see this hospital listed.)
Other reports tell of feeling "chills" in a certain spot on the floor, and of finding out later that the same spot was where the spinning chair made it's debut. The ghost's haunting days may be over though, it turns out that the Hospital was bought by a church group and the holy men had the floor exorcised.