Designated in 1980 (Partial Nature Reserve), 1997 (Nature Reserve)

Paul do Boquilobo is a natural freshwater marsh situated on the last branch of the river Almonda on the right bank of the Tagus, in the alluvial plains near Golegã, in Santarém district. The area is naturally flooded in winter by the Tagus and part of it subsequently dries out, leaving some cultivated areas. This wetland is characterised by its long network of ditches, flooded throughout the year, with seasonal overflow from the Almonda and Tejo rivers. The hydrology and soil have been extensively modified by humans for many centuries in order to create cultivated areas and to protect against flood erosion.
In the central zone of Paul do Boquilobo natural and semi-natural habitats predominate. The main watercourses are bordered by riparian galleries, with willow Salix spp., ash Fraxinus angustifolia and poplar Populus nigra. In the cultivated flood-plain species like the bulrush Scirpus lacustris, reed Phragmites australis, small reed mace Typha angustifolia, couch grass Paspalum paspaloides and water smartweed Polygonum amphibium dominate. There is one area of oak-woods with Mediterranean characteristics, in which cork-oak Quercus suber, wild olive Olea europaea sylvestris, Portuguese oak Quercus faginea and holm oak Quercus rotundifolia predominate.
Paul do Boquilobo is the home of some of the most important colonies known of the spoonbill Platalea leucorodia, little bittern Ixobrychus minutes, and cattle heron Egretta garzetta, in addition to other species that nest here, like the grey heron Ardea cinerea, squacco heron Ardeola ralloides, night heron Nycticorax nycticorax, black-winged stilt Himantopus himantopus, and whiskered tern Chlidonias hybridus. It is an important wintering place for ducks, the most abundant species being mallard Anas platyrhynchos, wigeon Anas penelope, teal Anas creca, shoveler Anas clypeata, and pochard Aythya farina. It is also one of the few places where the red-crested pochard Netta rufina and garganey Anas querquedula nest.
For a long time Paul do Boquilobo preserved many human activities, including farming, horse-raising and traditional fishing. This protected area is a harmonious combination of water and birds in a Nature Reserve.