The Paul de Arzilla Nature Reserve was created to protect an important internationally recognized swampy area in the Ribeira de Cernach, next to the Mondego River, and includes part of the municipalities of Coimbra, Condixa and Montemore-o-Velho, and includes the valleys of Moinos, Mio and Costa and a group of dense forests. The reserve is also characterized by abundant water, and includes a group A very diverse range of plants attracts a large number of animal species, including ducks and different types of herons that build their nests throughout the area.