The Greek term karyatides literally means “maidens of Karyai,” an ancient town of Peloponnese (southern Greece). Karyai had a famous temple dedicated to the goddess Artemis in her aspect of Artemis Karyatis: “As Karyatis she rejoiced in the dances of the nut-tree village of Karyai, those Karyatides, who in their ecstatic round-dance carried on their heads baskets of live reeds, as if they were dancing plants” (Kerenyi 1980 p 149).
The Erichtheion, a temple which stands next to the Parthenon, is home to the archetypal caryatids. They have launched a thousand imitators, from Augustus Saint-Gaudens to Victorian-era furniture makers. Lord Elgin carried one back home to England, after accidentally smashing another. Originally six in number, five of these enormous stone women remain at the Erechtheion, while one is hostage to the British Museum (the caryatid Elgin smashed was repaired with cement and rebar).
Thanks to Wikipedia for the photo and nut-tree village quote (walnuts, in case you were wondering).