Limits of the areas of natural interest defined in Decree 328/1992, which approves the Plan of areas of natural interest (PEIN), and any subsequent modifications that may have occurred. This base includes spaces at a scale of 1:50 000 and, in some cases, 1:5 000. The PEIN establishes a network of spaces representative of the rich landscape and biodiversity of the territory of Catalonia, from high mountains to coastal plains, and from Euro-Siberian forests to semi-desert wastelands or marine spaces. The PEIN is the higher level planning instrument that structures the system of protected areas of Catalonia and integrates this system within the whole territory, as it is a sectorial territorial plan framed within the Territorial Plan of Catalonia (1995). Subsequent to its approval, specific modifications to the rules and limits have been approved by decree, as well as extensions or additions of new spaces.

Limits of the figures defined in Law 12/1985, of natural spaces: national park, natural places of national interest, natural reserves and natural parks. It also contains the limits of wildlife reserves defined in Legislative Decree 2/2008, of 15 April, approving the Revised Text of the Animal Protection Act. The limits of each space are established in the legal regulations by which the space is declared or modified.

Boundaries of the natural spaces of Catalonia that form part of the European Natura 2000 network. Natura 2000 is a European ecological network of areas that may have been proposed as special protection areas for birds (ZEPA) in accordance with the Directive 2009/147/CEE, also known as the Birds Directive, and/or as Special Areas of Conservation (ZEC) in accordance with Directive 92/43/CEE, also known as the Habitats Directive. In the first instance, the Government of Catalonia approves the proposal for sites of Community importance (LIC) for the Natura 2000 network of the areas of the Alpine and Mediterranean biogeographical regions. Subsequently, the European Commission adopts the conformity of this proposal and finally the Government of Catalonia declares the LICs as ZECs.