As home to Project Blue Book, ground zero for a government investigation of UFOs from 1951 to 1969, Wright Field (now Wright-Patterson Air Force Base) outside Dayton, Ohio, ranks up there alongside Area 51 as a subject of enduring speculation.

Many of the rumors surrounding Wright-Patt, as it’s known for short, involve what might have gone on inside a particular building, known as Hangar 18. UFO enthusiasts believe the government hid physical evidence from their investigations—including flying saucer debris, extraterrestrial remains and even captured aliens—in this mysterious warehouse, specifically inside a sealed, highly guarded location dubbed “the Blue Room.”

The legend of Hangar 18 goes back to the supposed crash of a UFO in the desert near Roswell, New Mexico, in July 1947. According to a press release issued by the Roswell Army Air Field (RAAF) at the time, their personnel inspected the “flying disc” and sent it on to “higher headquarters.” A subsequent press release from an Air Force base in Fort Worth, Texas (assumed to be the aforementioned headquarters) claimed the disc was a weather balloon—a claim the Air Force acknowledged was untrue in 1994, admitting it had been testing a surveillance device designed to fly over nuclear research sites in the Soviet Union.

But in addition to Fort Worth, many UFO researchers believe some of the materials from Roswell were also transported to Wright Field after the crash and stored in Hangar 18, based on unsubstantiated reports from former military pilots. One, Oliver Henderson, reportedly told his wife that he flew a plane loaded with debris, along with several small alien bodies, from Roswell to Wright Field. According to the children of another pilot, WWII ace Marion “Black Mac” Magruder, their father claimed to have seen a living alien at Wright Field in 1947 and told them “it was a shameful thing that the military destroyed this creature by conducting tests on it.”

Senator Barry Goldwater of Arizona, the Republican nominee for president in 1964, was notoriously fascinated by UFOs and Hangar 18. Goldwater said publicly that he tried to gain access to the Blue Room in the early ‘60s, but had been denied access by a furious General Curtis LeMay.

Even after Project Blue Book wrapped up in 1969, rumors continued to swirl around Wright-Patt. In 1974, a Florida UFOlogist named Robert Spencer Carr publicly claimed that the Air Force was hiding “two flying saucers of unknown origin” inside Wright-Patterson’s Hangar 18, according to a report in the Tampa Tribune. Carr claimed to have a high-ranking military source, who saw the bodies of 12 alien beings while autopsies were being performed on them. Though Carr’s claims were dubious, widespread media coverage of them, as well as the release of the 1980 movie Hangar 18, helped cement the legend of Wright-Patt as a hotbed of the government’s UFO-related activities.

For its part, the Air Force has categorically denied the rumors and maintains there has never actually been a Hangar 18 anywhere on Wright-Patt, though there is a Building 18.

“Periodically, it is erroneously stated that the remains of extraterrestrial visitors are or have been stored at Wright-Patterson Air Force Base,” the Air Force said in an official statement issued in January 1985. “There are not now, nor have there ever been, any extraterrestrial visitors or equipment on Wright-Patterson Air Force Base.”