In the northern part of the capital lies the town Bacnotan. It is popularly known as the Home of Mushroom, Silk, and Honey. This town is also home to Holcim Cement Plant, the State University, and the fisheries research center among others. Surfing has likewise caught up with the trend in the neighboring San Juan town. Trade and industry in Bacnotan is so diverse that its economic development is brought to a sustainable level over the years. A 1st class municipality located in the first district of La Union, the road network is so developed making travelling a sheer pleasure. Bacnotan can be reached by all means of land transportation. The central business district is conveniently located along McArthur Highway.

With 6,507 hectares in land area which is comprised of coastal, plain, and mountainous land, Bacnotan is easily accessible. It is bounded on the north by the town of Balaoan; on the east by San Gabriel town; on the south by the Surfing Capital of the North that is San Juan; and on the west by the West Philippine Sea. Based on the 2015 census, it has a population of 42,078.

The town of Bacnotan was formally founded in 1599. When La Union was created in 1850, Bacnotan was included within the territorial jurisdiction of the province. It is politically and administratively subdivided into 47 barangays; to wit:

Places of interests and Events:

• Town Fiesta/Diro Festival: December 27 to 30
• Parochial Fiestas: September 29, feast of St. Michael the Archangel; and
  May 1, feast of St. Joseph the Worker.
• DMMMSU: National Apiculture Research, Training and Development Institute
  (NARTDI)
  Sericulture Research Development Institute
• Baroro River Cruise