thought to be at least 35,000 years old, the oldest depiction of a human figure found to date... see bbc article for more
for celtic Irish and British versions, Sheela na Gigs - see here. there are over 100 known sheela na gigs around ireland.
mind-bendingly weird fact: i've just heard that if you gave everyone 2 square feet of space to stand you could fit the world population into County Roscommon. which i've just discovered is twinned with Tucson, Arizona. the only thing i can think they have in common is that neither has a shoreline. it certainly ain't the weather. still, if we were all to meet, probably best to choose Roscommon over Tucson, if only for the lack of cacti.