The Zoroastrian funeral structure where corpses are exposed is called a dakhma.
Often translated as a “Tower of Silence,” a dakhma is a circular, raised structure designed to keep a dead body from directly contaminating earth, fire, or water. In traditional Zoroastrian practice, specially appointed corpse-bearers placed bodies on the structure, where exposure to sun and birds of prey helped reduce the remains.
This practice reflects the Zoroastrian concern with ritual purity and the destructive power of nasu, the pollution associated with death. After natural exposure, bones could be collected in an ossuary pit or central well. The exact design and customs varied across regions and periods, so “Tower of Silence” is a common English label rather than the original Persian term.
A dakhma is not a pyramid, stupa, or ziggurat. Those are monumental or religious structures from other cultural traditions and do not describe this Zoroastrian funerary use.