These are the ruins of once massive dams that fed the largest artifical reservoir of the world in the 11th century. The Bhojatāla or Bhoja's Lake was a hydraulic engineering marvel. It was formed by building 3 dams and diverting 2 rivers in a depression surrounded by hills.
The entire reservoir was destroyed by Hoshang Shah Gori, the Sultan of Malwa in the 15th century. The Mohammedan army spent 3 months breaking all the dams and then spent 3 entire years emptying the entire resevoir until it was just marshy uninhabitable barren land.
The Bhoja Lake had fed the region for 400+ years and once it was emptied by Hoshang Shah, it stayed uninhabitable for 30 years.
A small upper part of the lake still survives
A map showing the original size of the lake at Bhojpur.