The Apadana was the largest building on the Terrace at Persepolis and was excavated by the German archaeologist Ernst Herzfeld and his assistant Friedrich Krefter, and Erich Schmidt, between 1931 and 1939. Important material relevant to the excavations are today housed in the archives of the Freer Gallery of Art in Washington, DC.
It was most likely the main hall of the kings. The columns reached 20m high and had complex capitals in the shape of bulls or lions. Here, the great king received the tribute from all the nations in the Achaemenid Empire, and gave presents in return.
Access to the hall is given by two monumental stairways, on the north and on the east. These are decorated by reliefs, showing delegates of the 23 subject nations of the Persian Empire paying tribute to Darius I, who is represented seated centrally. The various delegates are shown in great detail, giving insight into the costume and equipment of the various peoples of Persia in the 5th century BC. There are inscriptions in Old Persian and Elamite.
The Apadana at Persepolis has a surface of 1000 square metres; its roof was supported by 72 columns, each 24 metres tall. The entire hall was destroyed in 331 BC by the army of Alexander the Great. Stones from the columns were used as building material for nearby settlements. By the start of the 20th century, only 13 of these giant columns were still standing. The re-erecting of a complete, but fallen column in the 1970s, is now the 14th standing column of the Apadana.
The Apadana in Susa was — like the city itself — largely abandoned, and pillaged for building material.