Hundru Falls is one of the strongest day trips from Ranchi. The Subarnarekha River drops off the plateau in a high, broken curtain of water, with rocky viewpoints and pools below when conditions are safe.
The falls are most impressive after the monsoon, but that is also when currents and slippery rocks are most dangerous. Use the official paths, listen to local warnings, and do not climb down close to the water in heavy flow.