Zoroastrian Tower of Silence near Yazd, Iran

They would place the bodies of the dead on top of these towers to let them be ‘cleansed’ by sunlight and carrion birds. It could take up to a year. A process called ‘excarnation.’

The bones would then be swept into an ’ossuary’ where they would get sprinkled with lye and eventually dissolve. The towers were built far from population to reduce chance of smell or runoff into water supplies.

They were still practising this in India until early 20th Century.