Roswell, New Mexico
The town of Roswell in SE New Mexico is, in skeptical circles at least, most famous for the alleged "UFO incident" that occured in June 1947. A local worker noticed some patches of debris around 30-35 miles north of the city and, having heard reports about "flying discs", called the local US air base at Roswell. The next day a "man in plainclothes" accompanied him to the debris site and the two men found more examples of rubber, tinfoil, tough paper, and structural parts. Eventually the US military issued a press release stating that the crash was a weather balloon and a reflective "kite" attachment for reflecting radar signals back to the ground.
After that interest completely waned for more than 3 decades until UFO researchers started to investigate the incident and interview people associated with it. They obtained documents via the Freedom of Information Act and also looked at documents leaked by "insiders" that refer to Majestic 12 - a shadowy body that some people believe is closely related with the investigation of alien activity and the recovery of alien artefacts. They all came to the conclusion that a flying saucer of extra-terrestrial origin definitely landed there, and had no time for any conflicting, rational explanations.
In 1995 years a video tape surfaced purporting to be evidence of a supposed alien autopsy. It was released by a London-based businessman named Ray Santilli and he claimed the corpse was from the original crash at the time. Later it was revealed to be a "recreation" of a tape seen previously. So, probably OK to be skeptical about that one. The real use of the craft was not known until the 90s when the craft's real mission - nuclear test monitoring - was revealed. The craft was part of Project Mogul - started by the US military to try and use airborne microphones to listen for Soviet atomic bomb tests. No weirdness. Just a bit of secrecy that led to people adding 2 + 2 together and making five thousand.