The Caoayan River is a significant waterway located in the Philippines, specifically in the province of Ilocos Sur. It flows through the town of Caoayan and is known for its scenic beauty and ecological importance. The river serves as a vital resource for local communities, providing water for agriculture and daily activities. The river is also home to various species of fish and other aquatic life, contributing to the region's biodiversity. Its banks are often lined with lush vegetation, making it a picturesque spot for both residents and visitors. The Caoayan River plays a crucial role in the local ecosystem and economy.