Aalnia Dam is a modest reservoir south of Kota, but the real reason to come is the surrounding rock-art landscape. The nearby shelters contain prehistoric paintings, usually discussed as Aalnia rock paintings, showing animals and human figures in the ochre tones common to central Indian rock art.
This is a low-key, self-reliant excursion rather than a polished attraction. Go with local advice, carry water, and treat the painted shelters gently; the value is in seeing very old human marks in a landscape that most visitors to Kota never reach.