According to the Walloon Government Decree of 16th July 1985, "A Nature Park is a rural area of great biological and geographical interest, subject to measures designed to protect its environment, in harmony with the aspirations of the populace and the economic and social development of the area in question". Its area is at least 5,000 hectares all in one piece.

Unlike a nature reserve, a Nature Park does not impose any particular constraints on its inhabitants.

A nature reserve is a strictly protected area where biotopes are maintained and restored by appropriate management (managed reserve) or where natural phenomena are allowed to develop (integral reserve).

Reserves are managed either by the Region (State nature reserve), private associations and institutions, or private individuals (private nature reserve).