Covering 700 acres, this massive hill fort could sustain a population of 50,000 for four years thanks to 84 reservoirs designed to collect and store rainwater.
Deep in the mountains of Siberia, on an island in Lake Tere-Khol, lies the 1,300-year-old mystery of . This isolated fortress, with 10-meter-high clay walls, has puzzled archaeologists for decades because it shows almost no signs of ever being lived in. Modern research suggests it may have been built in 777 AD as a Manichaean monastery during a religious shift in the Uighur Khaganate, only to be abandoned shortly after when the ruler who commissioned it was killed. Indomitable Walls: The Greatest Defenses Kumbhalgarh Fort ClosedKumbhalgarh, Rajasthan, India Covering 700 acres, this massive hill fort could
This massive island fortress off India's west coast is famously the only one in the region never to be conquered, successfully repelling attacks from the British, Portuguese, and Dutch for centuries. Chittorgarh Fort ClosedChittorgarh, Rajasthan, India Modern research suggests it may have been built