[3][4] It is located in the municipalities of Bunawan, La Paz, Loreto, Rosario, San Francisco, Talacogon, and Veruela in the province of Agusan del Sur.

Found in the heart of Mindanao's Agusan Basin, this vast expanse of marsh covers an area roughly the size of Metro Manila.

In the dry months, thousands of birds come from as faraway as Japan, China and Russia to escape the chilly winter winds of Northern Asia.

The marsh has been designated an Important Bird Area (IBA) by BirdLife International because it supports significant populations of Philippine ducks, spotted imperial-pigeons, sarus cranes, purple herons, Pinsker's hawk-eagles, southern silvery and rufous-lored kingfishers, and celestial monarchs.

[8] In the very heart of the marsh is a semi-permanent lake where many square kilometres of lily pads, hyacinths and other hydrophytic plants spread out like an enormous green quilt.