Here are some interesting pictures of historical religious sites from the ancient Persian empires.These ancient sites (there are quite a few of them) are found in Iran (Persian Empire) as well as throughout Central Asia and going into the Caucasus (Samarkand, Bokhara, Chechnya (Vainakhs).
The first two pictures here show what is known as the Ka'ba Zartosht.
"The Ka'ba-ye Zartosht (alt: Kaba-ye Zardusht, Kaba-ye Zardosht, Persian: کعبه زرتشت), meaning the "Cube of Zoroaster," is a 5th century B.C.E. Achaemenid-era tower-like construction at Naqsh-e Rustam, an archaeological site just northwest of Persepolis, Iran. This enigmatic structure is one of many surviving examples of the achaemenid architectural design."
In Persian, Ka'ba meant a cube, from which the English word 'cube' is also derived.
The picture below here is the Tomb of Cyrus The Great, the Persian Emperor who was also a Zoroastrian.
Cyrus' Tomb has also become a sacred site where Zoroastrians still go to pray. Look at the pictures below. People praying at the Tomb of Cyrus The Great.