It all sounds like an Agatha Christie novel. Many will say (myself as well) there's a logical explanation to everything, Poirot certainly would. If anything, these situations are examples of ingenuity, hoaxes, crime, then again you never know. On the Unexplained mystery site there are a few unsolved mysteries that border on urban legend rather than fact. Simply a successful crime? A missing wealthy diplomat goes to a crime ridden bar? Well you don't even need to be Sherlock for that.
Child Star disappears without a trace
Promising actor child actor Joseph Pichler (Varsity Blues, The Fan) vanished after a party in the early hours of Jan. 5, 2006. With no signs of foul play his apartment was found unlocked with a television on and his car abandoned parked behind a Mexican restaurant. His file remains an active missing persons case.
The Bennington Triangle
Another take on the Bermuda Triangle or Devil's Sea? There are numerous explanations of why planes and ships have disappeared in the ocean, human error, weather or other 'Acts of God', but this town does sound a bit creepy.
Foul play? Not without a body I suppose.
A Colony deserted
"The Disappearing Colony of Roanoke: In 1587, John White founded a colony of 114 men, women and children in the new world on Carolina’s coast. They struggled to survive on Roanoke Island, but as times were tough, John decided to return to England for supplies. When he returned 3 years later, to his amazement the colony had disappeared. He could not find a trace of anyone anywhere, yet personal belonging remained in place, untouched. The only clue spotted was a carving in a tree trunk of the letters CRO."
On trivia-library.com there seems a viable explanation. In 1719 over a century after the mysterious desertion, a tribe of Indians just 100 miles inland from Roanoke were discovered to have attributes of unusually light skin, some with gray eyes, who spoke English. The 1790 census was that 54 of the 95 family surnames were of the lost colonists.