The National Observatory of Athens (NOA) is the oldest Greek public research centre (founded in 1842). It hosts the UNESCO Chair for Natural Disasters and operates the Greek GEO Office (Group on Earth Observations).

NOA’s Institute for Environmental Research & Sustainable Development (IERSD) maintains the longest and most complete climatologic record in Greece of meteorological (>120yrs) and solar radiation (>60yrs) parameters. It was also the first organisation that started a systematic study of urban pollution in Athens, in 1980. The Institute’s research orientation includes: meteorological monitoring (260 stations), experimental research on air quality, atmospheric chemistry, aerosols and solar radiation, climate change research, synoptic and mesoscale atmospheric modeling, applied research (buildings, indoor air pollution, energy conservation, consultant services, e.t.c.), environmental management, surface and underground hydrology.

The Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing (IAASARS) is one of the three institutes of the National Observatory of Athens, the oldest research institution in Greece. The main activities of the Institute involve basic and applied research in a number of topics in astrophysics, from distant galaxies to the solar neighbourhood, as well as ground based and space-borne remote sensing, earth observation and signal processing. The institute is also committed to outreach and science dissemination for the general public and operates a very popular visitor centre in Penteli.