"Originally, the site of Mohenjo-daro must have been much more extensive than it is today and have formed a more closely connected whole, but water and wind, aided by the action of salt in the soil and the extreme aridity of the climate, have combined to eat deeply into the sides and carve deep furrows and hollows through its middle, leaving only here and there mere fragments of later cities," wrote John Marshall in 1931. The bund and spurs in the Indus in the top right are meant to protect the site from flooding; the white around the site itself is salt.
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