Caoayan located in the administrative territorial entity Ilocos Sur
Caoayan, officially the Municipality of Caoayan (Ilocano: Ili ti Caoayan; Filipino: Bayan ng Caoayan), is a 4th class municipality in the province of Ilocos Sur, Philippines. According to the 2020 census, it has a population of 19,574 people.Etymology
During pre-Spanish times the port of Pandan was an important trading post for Chinese and inter-island vessels, and one of the commodities once traded there was bamboo.  With the arrival of the Spaniards came the project to identify the names of places in the Philippines.  Spaniards, patrolling the area for pirates known as tirong, came to a place near the island called Puro, and asked the name of the place.  Thinking that the Spaniards wanted to know the name of the bamboo floating in rafts on the Baggoc River waiting to be traded, they answered "kawayan."  The Spaniard then listed the place's name as Caoayan.
From that time on, the place's registered name was Caoayan, and has been registered as a barrio of the capital town Bigaan.  It became a parish in 1825. The first missionaries that founded Saint Paul College of Ilocos Sur landed in Pandan. A commemorative marker stands at Pandan Port to commemorate the event.Government
Local government
Caoayan, 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. The mayor, vice mayor, and the councilors are elected directly by the people through an election which is being held every three years.
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