Zoroastrians, followers of
the world's oldest monotheistic religion, believe both fire and earth must
be kept pure. That means bodies cannot be cremated or buried, so until the
1960s their dead were placed in the hilltop "Tower of Silence" in the
background to be pecked clean by vultures. These days Iran's Zoroastrians
are buried in concrete-lined graves to avoid contaminating the earth. The
brick dome in the foreground covers a water cistern; the "wind towers"
funnel breezes into the cistern to keep the water cool.