Santol (Sandoricum koetjape) is the name of the tree bearing round, yellowish fruits growing in abundance in the municipality, notably in Barangay Pussuac.

He finally found many santol-bearing trees in a place north of Bantaoay now called Barangay Pussuac.

[citation needed] Don Pablo Arquero is claimed to have founded the municipality on May 12, 1742, with Father Tomas Millan as the first parish priest.

Father Millan laid the foundation of the belfry, where the great Filipino hero Diego Silang once worked as a boy.

Poverty incidence of Santo Domingo Source: Philippine Statistics Authority[11][12][13][14][15][16][17][18] Santo Domingo, belonging to the first congressional district of the province of Ilocos Sur, is governed by a mayor designated as its local chief executive and by a municipal council as its legislative body in accordance with the Local Government Code.