Based around a water storage reservoir built in 1976 under the Khmer Rogue by slave labor, this wetland bird sanctuary occupies 19 sq miles  (49 sq km). A mixture of grass- land, diptero carp, and paddy fields, the area was officially declared a Sarus Crane Reserve by royal decree in 2000. The sarus crane is an extremely rare and elegant bird depicted on bas-reliefs at the Bayon. Besides being a feeding ground for 300 sarus cranes, Ang Trapeng has more than 200 other species of birds, 18 of which have been classified as globally threatened. In  addition to the birds, visitors may chance upon the large  fruit bats that inhabit semi- submerged trees on the edge  of the reservoir. The very fortunate may also sight the rareeld’s deer.

It is possible to tour the preserve on a boat, but visitors must register at the Wildlife Conservation Society Office in the adjacent village first. While most people visit the preserve on a day trip from Siem Reap, overnight stays can also be organized through the Sam Veasna Center in Siem Reap.