Ka'ba-ye Zartosht

 temple, memorial, place with historical importance, interesting place

Ka'ba-ye Zartosht (also Kaba-ye Zardusht, Kaba-ye Zardosht, Persian: کعبه زرتشت), meaning the "Cube of Zoroaster", is a 5th century BCE Achaemenid-era tower-like construction at Naqsh-e Rustam, an archaeological site just northwest of Persepolis, Iran.

The name probably dates to the 14th century, when many pre-Islamic sites were identified with figures and events of the Koran or the Shahnameh. In reality, the structure is not actually a Zoroastrian shrine, nor are there reports of it ever having been a pilgrimage site. The structure, which is a copy of a sister building at Pasargadae, was built either by Darius I when he moved to Persepolis, or by Artaxerxes II, while the walls surrounding it dates to Sassanid era.

From a reference to fire altars, in a Sassanid-era inscription on the building, it was inferred that the structure was once a fire altar, or perhaps used as an eternal-flame memorial to the emperors whose tombs are located a few meters away. However, many scholars consider the structure to be an Achaemenid royal tomb, and it has been observed that both the Ka'ba and the sister building at Pasargadae correspond more closely to the description of Cyrus's tomb by Arrian(6.29) and Strabo(15.3.7) than does the monument in Pasargadae which is commonly attributed to this king.