Dairi is a regency in North Sumatra Province with the capital city is Sidikalang. This regency was divided into two regencies i.e Dairi Regency as the main and established Pakpak Bharat Regency based on Law No. 9 of 2003 concerning the Establishment of South Nias Regency, Pakpak Bharat Regency and Humbang Hasundutan Regency issued on February 25, 2003.
Dairi Regency is one of 33 regencies / cities in North Sumatra Province with total area of 192,780 ha, which is about 2.69% of the area of North Sumatra (7,160,000 ha) located in the northwest of North Sumatra Province. In general, Dairi Regency is at an average height of 700 to 1,250 m above sea level, with total of districts are 15 districts.