As you know today Iran is an Islamic country, but it wasn’t always like this. 2000 years ago the only religion in Iran was Zoroastrian. Teachings of Zoroaster were sacred and none would disrespect them.
Zoroastrian tradition about the dead was a little different. They believed dead bodies can be contaminated by demons and in order to purify them, they would expose the bodies to natural elements like sun, air, fire and wild animals until they would completely cease to exist. An unusual but ancient tradition, dating back to 3000 years ago.
The bodies were placed in a circular form, children in the center, women in the middle and men in the outer circle. After the purification the bones were placed inside or around a tower of silence. So in a way we can say that towers of silence are sacred mass graves.
There used to be many towers in Iran but after the fall of Persian empire most of them were destroyed. There are also towers of silence in India, although the most prominent “Towers of Silence” are in Iran.
The towers are not used in ceremonies anymore but they can be visited as a tourist attraction. Towers of silence are some of the most mysterious buildings in the world and can be compared to tombs of Egyptian Pharaohs.