Kŭmgang lies immediately north of the Korean Demilitarized Zone.

The Taebaek Mountains pass through the county, reaching their highest point in the Pirobong peak of Kumgangsan.

Kŭmgang county is divided into 1 ŭp (town) and 26 ri (villages): The chief local industry is agriculture, with rice and maize the dominant crops.

Manufacturing and livestock raising also contribute to the local economy.

Mining is supported by deposits of gold, tungsten, and quartz.