Answer : 2. "नक्की"
Explanation :

Nakki Lake is the biggest attraction of Mout Abu, in Rajasthan, India. It is the largest manmade lake at the height of 11, 00 meters in India and is romantically called the love lake of Mount Abu. It is the sacred lake for the proud Garacia tribe. Legends say that it was dug out by bare nails - thus the name Nakki.