Tamam Shud case
Considered to be one of Australia's most profound mysteries, the Tamam Shud Case revolves around an unidentified man found dead in December 1948 on Somerton beach in Adelaide, Australia. Aside from the fact that the man could never be identified, the mystery deepened after a tiny piece of paper with the words "Tamam Shud" was found in a hidden pocket sewn within the dead man's trousers. (It is also referred to as "Taman Shud.")
The phrase translates as "ended" or "finished" and is a phrase used on the last page of a collection of poems called “The Rubaiyat” of Omar Khayyam. Adding to the mystery, a copy of Khayyam's collection was later found that contained a scribbled code in it believed to have been left by the dead man himself.
Due to the content of the Khayyam poem, many have come to believe that the message may represent a suicide note of sorts, but it remains uncracked, as does the case.