It is a great puzzle - a surefire hit in the classroom. But what makes me love this puzzle so much is the simple fact that it is a hoax. Traditionally there was no such legend in Vietnam - or in India either, which is another popular location for the site of the temple. The whole thing is the invention of mathematician Edouard Lucas. When the puzzle was first published in 1883 it appeared complete with legend and was credited to N. Claus de Siam (an anagram of Lucas d’Amiens - Amiens being the town of his birth).