A location referred to as "Parthenon" appears in the fifth-and fourth-century BCE inventories of Athena's riches as one of the treasuries on the Acropolis of Athens, along with the Hekatompedon, the Proneos, the Opisthodomos, and the Archaios Neos. It is usually identified with the west room of the building today known as the Parthenon. Here, I offer a thorough review of the epigraphical, archaeological, and literary evidence and propose that the treasury called the Parthenon should be recognized as the west part of the building now conventionally known as the Erechtheion. 1 introduction Why do we call the Great Temple on the Athenian Acropolis the "Parthenon," or Virgin Room? The usual answer is that the name derives from the divine resident of the building, Athena Parthenos. Her colossal chryselephantine statue stood in the temple's cella, the great room opening to the east (fig. 1). However, in the fifth and fourth centuries BCE, long before the earliest attestations of the name "Parthenon" for the whole temple, the statue is mentioned in the inventories of treasures inside the "Hekatompedos Neos" (Hundred-Foot Temple). This, then, was the name of the cella, the only possible location of the statue. In those same centuries, separate inventories were made of a different treasury on the Acropolis, also called "Parthenon. " Where, then, was this Parthenon treasury located, and what is the origin of its name?Under the assumption that the Parthenon treasury must be a part of the building that was later called the Parthenon, scholars have nearly unanimously identified the Parthenon treasury with the west room of the Great Temple (the room with four columns that opens to the west in fig. 1, hereafter called the West Room). 2 It is not clear, however, why precisely this space 1 I am grateful to the Netherlands Institute at Athens, the Ephorate of Antiquities of Athens, and the German Archaeological Institute at Athens for their support. For astute comments that have greatly improved the article, I thank the editors of the AJA, the anonymous reviewers,