Adit to desilting chamber, part of the abandoned and unfinished Loharinag-Pala Hydro Power Project on the Bhagtrathi river (one of the headstreams of the Ganges river).
For more info about the Loharinag-Pala Hydro Power Project, read en.wikipedia.org/wiki/Loharinag_Pala_Hydro_Power_Project.