Leonardo Da Vinci spent a lifetime trying to paint one. Scientists and mathematicians have puzzled for centuries over what makes one, while cosmetic surgeons have amassed fortunes striving to create one.
And Florence Colgate? Well, she simply has one.
The 18-year-old student is blessed with what is described as the perfect face. It matches an international blueprint for the optimum ratio between eyes, mouth, forehead and chin, endowing her with flawless proportions.
In theory, that needn't necessarily cause her to appear anything more than symmetrical (in which department, incidentally, she is also faultless).
But the blue-eyed blonde's mathematical dimensions have just added up to success in a competition to find Britain's most naturally beautiful face.
Florence, who has a Saturday job in a seaside chip shop in between studying for her A-levels, beat 8,000 entrants to win the title. Contestants were judged without make-up and were barred entry if they had had plastic surgery or chemical enhancement.
Locals wryly suggested it was the sea air in the Dover Grammar schoolgirl's home town of Deal, Kent, which contributed to her success, or possibly a secret ingredient in Middle Street Fish Bar's chips.
But it is the scientific definition of beauty – not to mention a healthy portion of beauty genes from her mother – which gave Florence the crown.