The National Astronomical Observatory (NAO) Rozhen is the largest astronomical observatory in Southeastern Europe and on the Balkan Peninsula. The scientific complex is situated in the beautiful area on the ridge of the mountain, near the Rozhen peak (1750m).

The observatory was opened on March, 13, 1981 and is a part of the Astronomy Institute at the Bulgarian Academy of Science. The complex consists of several buildings – towers, where the telescopes are installed, a group of residential buildings, a meteorological station and the small chapel ‘Holy Spirit’.

The observatory has a 2m long, 80-ton telescope, one of the few top-class telescopes in the world, which is available to the public. NAO Rozhen is one of the most visited landmarks in the area. The complex hosts scientific meetings, scholarships and limited attendance workshops (up to 30 - 40 participants). There are also a visitor’s center, a lecturing room and a museum exhibition. Lectures and demonstrations are organized beneath the 2-metre telescope, for individual and group tourists.

The National Astronomical Observatory (NAO) Rozhen is listed in the 100 Tourist Sites in Bulgaria with number 83.