Explore the Montsec Observatory (OdM)

The Montsec Observatory (OdM) is a scientific and technological infrastructure managed by the Institute of Space Studies of Catalonia (IEEC) under an agreement with the Ministry of Research and Universities of the Generalitat de Catalunya.

It is located at 1570 metres above sea level in the Montsec mountains, in the municipality of Sant Esteve de la Sarga (Lleida). This area is recognised as one of the best in Europe for astronomical observation, thanks to the combination of good weather conditions and the low level of light pollution, which provide exceptional night sky conditions.

Usually, the OdM is not open to the general public, except for scheduled guided tours. We can get there from the north side of Montsec d’Ares, taking the detour on the C-13 towards Guàrdia de Noguera and continuing until 2 km after Sant Esteve de la Sarga, where we will find the detour on the left which goes up to the Ares pass and the observatory. Also, it can be reached from the south side, taking the detour to the C-12 in Àger and travelling 16 km to the Ares pass, where we will find the last section of the road to the observatory indicated.

The municipality of Sant Esteve de la Sarga, where the OdM is located, is situated in the Pallars Jussà region, north of Montsec d’Ares. The area has a rich natural and cultural heritage, and is included in the Xarxa Natura 2000, which provides it with special protection to preserve its ecological and landscape values. The municipality has also enjoyed Starlight Reserve certification since 2013.


42° 03′ 05″ N, 00° 43′ 46″ E


1570 m



What do we offer?

Find out about the Observatory’s services


The OdM includes three astronomical research equipments, two atmospheric measurement stations, and a satellite communications station

Live cameras

See for yourself the facilities and the live views from the Observatory


Check live weather data and those of the last few days

Image gallery

Astronomical pictures and photographs of the Observatory’s facilities

Staff directory

Meet the team behind the Observatory


Would you like to visit the Observatory? Do you have any questions about our research? Drop us a line!