Mahasu/masto Devta Temple, is located on the Tuini-Mori road at Hanol. The temple is dedicated to Mahasu Devta. Lord Mahasu is the chief deity of this area and is worshipped in Mahasu Devta Temple by the people of Hanol and nearby villages of Uttarakhand and Himachal Pradesh state of India. It is the ancient temple of Mahasu Devta built in the 9th century. The temple was constructed in Kath-Kuni or Koti-Banal style of architecture. It is included in the Archaeological Survey of India list of the ancient temple in the Dehradun circle, Uttarakhand.
Mahasu Devta Temple is on the eastern bank of Tons River at Hanol village, near Chakrata, about 190 km from Dehradun, 156 km from Mussoorie and about 140 km from Shimla.