First time when I saw the photos on net, I couldn't believe it. Last year, managed to go there personally to experience this place.
We went in November, which was a little after monsoon, but much earlier to a summer. Hence the weather was decent. Also water level in the river pennar was about to go dry. Only few patches of water was left.
It is possible to trek all the way down till riverbed.
The otherwise plain area and sudden depth of the valley
What else is nearby?
Belum Caves, Hosley Hills, Talakona, Tirupati are other destinations within drivable distance from Gandikota
How to go to Gandikota?
Gandikota is some 100kms from Kadapa. Local buses are available, but their timings not so frequent. Personal vehicle is the best option. Not much shops/hotels available, so be sure to carry whatever you need. An APTDC hotel is available in Gandikota which has accommodation and sells meals