Which religion exposes the corpses of dead believers on "Towers of Silence"?
Zoroastrian tradition considers a dead body (in addition to cut hair and nail parings) to be potential pollutants. Specifically, the corpse demon was believed to rush into the body and contaminate everything it came into contact with, hence the ecclesiastical code "given against the demons" has rules for disposing of the dead as "safely" as possible.
To preclude the pollution of earth or fire, the bodies of the dead are placed atop a tower and so exposed to the sun and to scavenging birds. Thus, "putrefaction with all its concomitant evils... is most effectually prevented."
Although there are superficial similarities with Tibetan "Sky Burial" the Towers of Silence are purely Zoroastrian.
Indian Parsi communities have resorted to "solar collectors" in recent times because of the decline in the number of vultures, resulting from diclofenac poisoning.