Rouge-Cloître forms an architectural, woodland and natural ensemble of great richness. The nature of the soil and the abundance of wetlands make it a place with a special alchemy, highly appreciated by Brussels residents.

The presence of one of the largest priories of Augustine canons in Brabant for centuries has of course marked the landscape.

On the site of the former sandstone quarry grows vegetation typical of calcareous soils, including orchids. A flooded alder grove occupies the site of an old filled-in pond.

The five ponds attract aquatic birds such as the crested grebe, heron, kingfisher and great cormorant. They are also reproductive sites for protected amphibians and fish such as the perch, the pike or the rare amur bitterling. Thirteen varieties of bats have been observed on the site.

Several areas not accessible to the public constitute one of the nature reserves of the Forest of Soignes. The main concern of the site managers is to channel pedestrian traffic and maintain the ponds and their banks in order to promote redevelopment of aquatic and marshland vegetation, reproduction of amphibians and nesting of aquatic birds.