Considered as the surfing capital of the north, the town of San Juan is found on the central part of La
Union Province. Located some 277 kilometers north of Manila, it is bounded on the north by the town of Bacnotan, on the east by San Gabriel, on the south by San Fernando City,
and on the west by South China Sea. The town is a third class municipality with a total land area of 57.2 square kilometers.
It is politically subdivided into 41 barangays.
San Juan is situated 277 kilometers north of Manila and 8.5 kilometers north of San Fernando City, the provincial capital.