The middle part of the third century AD is not well endowed with historical sources. We are largely dependent on later, often very abbreviated, texts. But about 50 years ago, an inscription was found in Persia, at Naqsh-e Rustam, which supplements these:
To these sources has recently been added a unique monument, the inscription of Shapuhr I, engraved on three walls of the first floor of the Kaabah of Zoroaster, the towerlike stone building of Achaemenian times which still stands in front of the rock cut graves of the Achaemenian kings of Persia near Persepolis at Naksh i Rustem (Pl. VII, 1-2).
The inscription which gives the same text in three languages, Arsacid Pehlevi, Sassanian Middle Persian, and Greek, was discovered in 1936 and 1939, by Dr. Erich Schmidt, director of the Iranian expedition of the Oriental Institute, University of Chicago. 
The "Kaabah of Zoroaster" is literally the "Cube of Zoroaster", and looks just like one. The plates showing the monument are these:via http://www.roger-pearse.com/weblog/?p=9036