Fiddler's Green is a legendary supposed afterlife, where there is perpetual mirth, a fiddle that never stops playing, and dancers who never tire. In 19th-century maritime folklore it was a kind of afterlife for sailors who have served at least 50 years at sea.
A song based on Fiddler's Green, called Fiddler's Green or more often Fo'c'sle Song, was written and copyrighted by John Conolly, a Lincolnshire (English) songwriter. The song was recorded by The Dubliners' 1973 Plain and Simple album and many other artists since then. The song is sung worldwide in nautical and Irish traditional circles, and is often mistakenly thought to be a traditional song.
A video for this song: