The Erechtheum, Athens, Greece

"Mnesicles, architect of the Propylaea, is thought to have been the architect of the Erechtheum, as well. It is believed he did not finish it. The main rectangle of the Erechtheum is 65.5' x 37 and rests on 3 steps. The north and west sides are about 9' lower than the others. The main structure of the Erechtheum has 4 parts including the porch of the maidens, in the southwest corner of the Erechtheum, where the columns are not the typical Ionic columns, but caryatids, one of which Lord Elgin removed,"--Erechtheum, by N.S. Gill, About Education website.

"The Ionic was chosen as the most suitable order for a temple built on two different levels to accommodate the uneven site. The eastern portico, distinguished by its slender Ionic columns, led to Athena's sanctuary, where an ancient wooden image of the goddess was housed, while the north porch, its stylobate ten feet lower, gave access to Poseidon's shrine through an even more elongated Ionic portico. Four Ionic columns, partially engaged in the wall, extend across the west facade to the south, where the roof of the splendid porch facing the Parthenon is supported by the six Caryatid maidens,"--Buildings Across Time: An Introduction to World Architecture, by Michael Fazio, Marian Moffett and Lawrence Wodehouse, 2009.