The Omagua (after the indigenous people of the Omagua ), also Selva baja ( Spanish " low-lying forest " ), Walla or anti, is by Javier Pulgar Vidal is the lowest altitude height step of Peru east of the Andes from about 80 to 400 m above the sea ​​and part of Amazonia.

The climate is hot with temperature averaging over 24 ° C. The relative humidity is high; there in summer precipitation peaks. The surface is flat, sometimes slightly wavy. There are very many, water-rich, slow- flowing rivers, which frequently change their riverbed. Lakes and swamps are also abundant.

The area is covered by tropical rainforest.

Since the dense vegetation is difficult to traverse, the rivers form the main arteries.