Beauty (n.). In women, an aspect that makes them socially mobile. In objects, high levels of useful functionality, relative to the observer's needs.
A concentration of beautiful women in any one place is a consequence of social inequality in the surrounding regions. A man drives his car down a country lane and slows down for a hitch-hiker. She is a young woman, unattractive and clumsy. He accelerates and drives on. Beauty gets women favours from men, makes them physically and socially mobile, takes them away from the barren countryside to the cities, to power, money, and pretty things.
Beauty is in the eye of the beholder, and everyone is a critic. A beautiful landscape is one that suits our ancestral human needs for space, protection, control. A beautiful car is one that carries us rapidly, safely, and with style - for cars are like the peacock's feathers, more a demonstration of the ability to waste, than utilitarian tools. A beautiful cathedral likewise is one that shows a pure elegance of waste. And a beautiful woman is, in every society, one with specific age and lifestyle indicators that correlate to "fertile, young, and available" (in the male eye) and "younger and more fertile than me" (in the adult female eye). Insofar as both these indicators and the eye for them are constant in all human groups, the criteria for human beauty can be considered universal.