| Antikythira Bird Observatory | Kythira Municipality | — |
 Corfu Observatory | Corfú | — |
| Efdoxos Observatory | Kefalonia Municipality | — |
| Ellinogermaniki Agogi observatory | Pallini Municipality | — |
| Holomon Observatory | — | — |
 Kryoneri Observatory | Sikyona | — |
| NOAK Observatory | Stavraki Ioanninon | — |
 Observatorio de Helmos | Municipio de Kalávrita | — |
 Observatorio Nacional de Atenas | Municipio de Atenas | 80 m |
| Penteli Magnetic Observatory | Dionisos Municipality | — |
 Penteli Observatory | municipio de Penteli | — |
| Santorini Volcano Study and Monitoring Institute | — | — |
 Skinakas Observatory | — | 1.750 m |
| Stephanion Observatory | — | — |