Sheela-na-Gigs are directly related to earlier Goddesses or Fertility figurines and the goddess symbolism of the early pre-historic and Celtic periods.  It is not certain how old the tradition may be or the precise age of some of the earliest examples but it appears that the Sheela-na-Gigs as we know it made its appearance during the latter part of the early Celtic Christian period and they were still being erected during the latter Middle Ages.

Six miles north of Ferbane are the remains of Doon Castle, with a carved figure called a "Sheela-na-Gig.  This is a well preserved Sheela-na-gig left of the doorway on the south east corner of the building.  The figure appears to have been carved standing though built into the castle on her site.