The Parthenon (Greek: Παρθενώνας) is the best-known surviving building of Ancient Greece and is regarded as one of the world's great cultural monuments. The building has stood atop the Acropolis of Athens for nearly 2,500 years and was built to give thanks to Athena, the city's patron goddess, for the salvation of Athens and Greece in the Persian Wars. The building was officially called the Temple of Athena the Virgin, and its popular name derives from the ancient Greek word παρθένος (parthenos), a virgin. The Parthenon replaced an older building that had been destroyed by the Persians. As well as being a temple, the Parthenon was used as a treasury, and was the location of the treasury of the Delian League, which later became the Athenian Empire. Although the nearby Temple of Hephaestus is the most complete surviving example of a Doric order temple, the Parthenon, in its day, was regarded as the finest. It was elaborately decorated with marble sculptures both internally and externally. These survive only in part, but there are good descriptions of most of those parts that have been lost. Beginning in 1975, the Greek Government, with funding and technical assistance provided by the European Union, began a concerted effort to restore the Parthenon and other Acropolis structures.