The Aigüestortes i Estany de Sant Maurici National Park is characterised by the wide diversity of aquatic ecosystems located here. There are more than 200 lakes within its boundaries, a fact that makes the Park the most important alpine lacustrine area of Europe. Since its beginnings, the LOOP has been in a close relationship with the Park, where part of its research has taken place. Since 2004, the LOOP carries out a monitoring programme in several lakes and streams of the Park. The LOOP is a founder member of the long term ecological research node LTER-Aigüestortes.
Limnological studies started in Lake Redon (formerly called Redó) in 1984. Since then, Lake Redon has been the flagship site of research of LOOP. More than 40 national and international projects have been carried out here. After nearly 30 years of continued research, Lake Redon is one of the most (if not the most) studied alpine lakes worldwide.