The Greek government has declared the entire, uninhabited island of Polyaigos a protected archaeological site, a landmark decision that will permanently shield the pristine Cycladic island from development.
The unanimous decision by the Central Archaeological Council (KAS) follows recent alarms raised by environmental groups and local communities over suspected illegal construction on the island.
The formal declaration is expected to be signed shortly by Culture Minister Lina Mendoni.
The new status protects not only the island's numerous archaeological remains, which date from prehistoric to post-Byzantine times, but also its unique natural habitat.
Polyaigos is part of the EU's Natura 2000 network and is a key refuge for the endangered Mediterranean monk seal.
Leaders of neighboring islands had feared the environmental and cultural degradation of Polyaigos.
"We will stand firm against anything that tries to alter the island's identity," said Konstantinos Ventouris, the mayor of neighboring Kimolos.