Old Persian is one of the two directly attested Old Iranian languages. Old Persian appears primarily in the inscriptions, clay tablets and seals of the Achaemenid era. Examples of Old Persian have been found in what is now Iran, Romania (Gherla), Armenia, Bahrain, Iraq, Turkey and Egypt, with the most important attestation by far being the contents of the Behistun Inscription. Recent research (2007) into the vast Persepolis Fortification Archive at the Oriental Institute at the University of Chicago have unearthed Old Persian tablets which suggest Old Persian was a written language in use for practical recording and not only for royal display.