"The Tachara may be regarded as a museum of the history of calligraphy, because its walls bear inscriptions of several ages: cuneiform texts by Darius, Xerxes and Artaxerxes III, Middle Persian texts by Sassanian scribes, Koofik Persian writings of the periods of the Buyid kings, Saljuquid and Timurid, princes and Safavid and Qajar governors."

The Tachara - Palace of Darius (Tachara of Darius, Mirror Hall) is one of the interior Persepolis Palaces. The meaning in olden Persian is wintry home.
The palace is made of gray stone. It was built by Darius I and was completed after his death in 486 by his son and successor Xerxes I.

A3Pa was added in the mid-fourth century to the newly-built western staircase of the Palace of Darius by Artaxerxes III Ochus.

Translation: http://www.livius.org/aa-ac/achaemenians/A3Pa.html