Between Mound AB and Mound F are a number of mysterious circular platforms, originally inside houses and small courtyards.
Slides of the mounds in Harappa and other archaeological sites in the Indus Valley by Omar Khan
These platforms are often called workmen's platforms, and were first thought to have been used to thresh grain for what was also thought to have been the nearby "Great Granary."
Close shot of re-constructed platform. The white is salt creeping up from the ground, a problem in many areas of the site.
The so-called "Great Granary" in Mound F. Its earliest levels date to 2450 B.C. A similar structure, also about 50 meters long and built on a massive brick or mud-brick platform, was found at Mohenjo-daro.
This unicorn seal was also discovered during the late 1927-31 excavations at Mohenjo-daro. One theory holds that the bull actually has two horns, but that these have been stylized to one because of the complexity of depicting three dimensions.
Individual rooms are 15 by 6 meters long, and have sleeper walls for airspace between them. At each end of the rooms are three raised platforms.
In addition to any commercial functions, the seal may also have designated a position of authority. The motif on the seal could also have been an amulet or charm. The seal itself was probably worn around the neck, with a chord passed through the boss
No grain, storage containers or clay sealings such as would have been attached to goods for shipment were found in the so-called "Granaries" of Harappa or Mohenjo-daro.
Although the Indus Valley script is still undeciphered, there is some agreement among a number of leading scholars that it represents some sort of proto-Dravidian language common in South India today.