Ka'ba-ye Zartosht (meaning the "Cube of Zoroaster") is a 5th-century B.C Achaemenid square tower.
The structure is a copy of a sister building at Pasargadae, the "Prison of Solomon" (Zendān-e Solaymān).
It was built either by Darius I (r. 521–486 BCE) when he moved to Persepolis, by Artaxerxes II (r. 404–358 BCE) or Artaxerxes III (r. 358–338 BCE).
The building at Pasargadae is a few decades older.
There are four inscriptions in three languages from the Sasanian period on the lower exterior walls.
They are considered among the most important inscriptions from this period.

Several theories exist regarding the purpose of the Ka'ba-ye Zartosht structure.
Ka'ba-ye Zartosht (meaning the "Cube of Zoroaster") is a 5th-century B.C Achaemenid square tower. The structure is a copy of a sister building at Pasargadae, the "Prison of Solomon" (Zendān-e Solaymān). It was built either by Darius I (r. 521–486 BCE) when he moved to Persepolis, by Artaxerxes II (r. 404–358 BCE) or Artaxerxes III (r. 358–338 BCE). The building at Pasargadae is a few decades older. There are four inscriptions in three languages from the Sasanian period on the lower exterior walls. They are considered among the most important inscriptions from this period.
Several theories exist regarding the purpose of the Ka'ba-ye Zartosht structure.
Naqsh-e Rostam