Kalvantin Durg is also called the Climb to Heaven. No rail on the edge and no ropes on the wall, God forbid if you have vertigo. Worst of all, the hardest part is coming down.
At the top of Kalavantin Durg you can see the Peb, Chanderi, Matheran, Karnala, and Ershal forts.
The city of Mumbai itself can also be seen. It is believed that the Fort was built around the time of Buddha or around or before 500 BCE.