Topchanchi Lake was built in 1915 as a reservoir near the foot of Parasnath Hill. It is one of the better short excursions from Dhanbad, with water, forested edges, and a slower pace than the city.
The lake is often combined with Gomoh, where Subhas Chandra Bose began part of his 1941 escape from British India. That gives an otherwise simple picnic lake a useful historical footnote.