Following is from the site http://www.orissatourism.gov.in/nrusingh.html.

Located in the sacred Gandhamardan Hills, which according to legends, Hanuman carried on his shoulders from the Himalayas as described in the ancient epic Ramayana, the temple at Nrusinghanath is an important pilgrimage site. It is also an exceedingly fascinating and beautifully  located temple and is worth the journey to this rather remote spot.

The present temple, located at the source of the Papaharini stream, is a 14th century structure built on a more ancient site. The four pillars within the Jagmohana suggest that the earlier temple was built in the 9th century. The beautiful doorframes have been dated to the 11th century.

The site of the temple is unique. Stone steps wind up the hillside behind the temple, leading past a  waterfall, and eventually curving under the falls to a spot where some beautiful, and very well- preserved relief sculptures are found. The climb to the carvings and return journey will take about an hour. Since shoes are not permitted on these sanctified pilgrimage steps, those with tender feet should take along a pair of heavy socks for the climb.

On the opposite slope of the hill on which the temple is located, is the Harishankar Temple. Between the two temples there is a 16 km. plateau, littered with Buddhist ruins that scholars feel may be the remains of the ancient university of Parimalagiri, referred to by the seventh-century Chinese traveler Hiuen T’sang as ‘Po-lo-mo-lo-ki-li’. The trek along this plateau is a long one, but for the serious student of history, it is an unforgettable experience.

Following is from http://www.mapsofindia.com/orissa/tourism/harishankar-falls.html.

he Harishankar Falls is located in Balangir, on the Southern slope of the Gandhamardhan hills. The waters of the Harishankar Falls gushes down the slopes in a series of captivating waterfalls that creates an out of the world scene.

At a distance of about 81 Kilometers is located the pilgrimage site of Harishankar. This locations is encapsulated in the charm of nature and is the shrine of the dual Hindu deity, Hari and Shankar. A very holy place for both the Vaishnavs and the Shaivites, Harishankar is the popular pilgrimage spot. The Harishankar Falls is a part of this pious place and the water of the Harishankar Falls cascades down to the granite floor of the shrines. The Harishankar Falls also acts as a natural shower for the pilgrims.

The site http://satyeshnaik.blogspot.com/2008/08/trip-to-nursinghnathnursinghanath.html has some beautiful pictures of the area.