The Agusan River is the third longest river in the Philippines and flows through the heart of the CARAGA region before emptying into Butuan Bay. The river delta around Butuan is the reason for the city's historical importance — it gave access to the interior of Mindanao for trade, and made the bay a natural harbour for the Chinese, Indian, and Malay traders who called here for centuries before Spanish arrival.
Boat trips on the river can be arranged locally and give a different perspective on the city and the surrounding delta landscape. The river is also the starting point for those heading inland to the Agusan Marsh Wildlife Sanctuary — a vast wetland area with endemic species including the Philippine freshwater crocodile, though reaching the marsh requires more commitment and time.