In the nature reserve northern part, Mourisca tide mill is the starting point of this small pedestrian route, with a great diversity of estuarine birds. Start at the information centre on the mill and ask for a brochure. Visit the mill and watch the birds on the river. Remember: these species are very sensitive to disturbance, so keep quiet while walking. Go out and head to the observatory built to allow a better observation and photography of the birds, so spend some time there in silence. Then, always paying attention to the water channels, walk to the old salterns. In winter, Sado Estuary hosts about 50,000 birds, including resident and migratory species. Spotlight on Eurasian spoonbill (Platalea leucorodia), little grebe (Tachybaptus ruficollis), grey heron (Ardea cinerea), Western marsh-harrier (Circus aeruginosus), black-winged stilt (Himantopus himantopus) and greater flamingo (Phoenicopterus roseus). Mourisca was one of the tide mills 4 known in Sado Estuary and worked until the 1950s, with around 250 years. After its acquisition by the State, recovery works were carried out and, in 2012, a co-management protocol was signed between ICNF, I. P. and C. M. de Setúbal. Nowadays, as well as an information and leisure centre, it is the beginning of two pedestrian routes: one in the estuarine, saltmarsh and old saltern areas; and the other in a more interior zone.