Hessdalen
Hessdalen is a village in the municipality of Holtålen in Trøndelag county, Norway. Hessdalen also refers to the  long valley that surrounds the village. Hessdalen is located in the central part of the village, approximately  south of the city of Trondheim, approximately  north of the mining town of Røros, and about  southwest of the village of Renbygda. About 150 people live in the village and surrounding valley. Hessdalen Church is located in the village of Hessdalen and the lake Øyungen lies about  southwest of the village. The Hessdalen area is known for the occurrence of unexplained aerial luminous phenomena called the Hessdalen lights. The phenomenon is monitored by the Hessdalen AMS. Name
The first element is the name of the local river Hesja and the last element is the definite form of dal, which means "dale" or "valley". References

Holtålen
Valleys of Trøndelag
Villages in Trøndelag