
Ecosystems and protection
Hymettus is protected as part of the Natura 2000 network. The Hellenic Ornithological Society lists the Site of Community Importance GR3000006 "Ymittos, Kaisariani Aesthetic Forest, Lake Vouliagmeni", of 8,819 hectares, covering 99% of the GR126 area.
Threats
- Fires. The Hellenic Ornithological Society names them the main threat to the qualifying species. Greek Wikipedia notes that the mountain has suffered destructive fires but keeps green areas thanks to continuous tree planting.
- Building. Loss of habitat from building spreading into farmland and shrubland on the fringes, and road opening (Hellenic Ornithological Society).
- Poaching. Listed as a threat by the same source.
- Landfills. English Wikipedia mentions six to seven landfills on the west side and one on the east.
On building, Kathimerini wrote in October 2019 that the Environment Ministry planned to extend a ban on construction on the slopes until October 2020, pending a presidential decree for the mountain’s protection.
In January 2020 the municipalities of the Association for the Protection and Development of Ymittos tabled a five-point plan: protection and preservation, establishing the mountain as a recreation point, environmental awareness, crisis-control mechanisms and technologies against fires and floods, and cultivating volunteerism (GTP Headlines).

Sources
- Hellenic Ornithological Society, Important Bird Area GR126 Mount Hymettus
- Kathimerini (English edition), "Mount Hymettus building ban to be extended", 1 October 2019
- GTP Headlines, "Preservation - Protection Plan for Attica’s Mt Hymettus Tabled", 27 January 2020
- Wikipedia (English), Hymettus
Not verified: whether the protection presidential decree mentioned in 2019 has been issued, or the current extent of building bans. The Natura code and area come from the Hellenic Ornithological Society. The official EEA Natura 2000 form did not load and was not used.