Observatorio Astrofísico de Javalambre (OAJ) is located at El Pico del Buitre (Vulture's Peak) (40° 02' 28.67'' North, 01° 00' 59.10'' West), 1957 meters above the sea level, close to the village Arcos de las Salinas (Teruel). In the picture below, the site of the observatory is shown on the right corner.
The properties of the atmosphere and sky at the site of the OAJ are described in Moles et al. (2010), PASP 122: 363.
The site has an excellent seeing, very low artificial light contamination and is typically above the inversion layer. The picture below was taken from Pico del Buitre, and shows the cloud cover below the mountaintop (images from CEFCA).