Fengari, Mountain summit in Samothraki, Greece.

Fengari, also called Saos, is the highest mountain on the Greek island of Samothraki, rising to 1,611 metres. Its summit is bare, rocky and serrated, while the lower slopes are wooded with oaks, pines and plane trees. The mountain occupies most of the island's central part and has many springs that flow even in summer.

In ancient times, sailors crossing the northern Aegean used the mountain's outline as a navigation point, and it appears in Homer's Iliad as the place where Poseidon watched the Trojan War. The peak was known as Saos before the current name took hold in later centuries.

The name Fengari means "moon" in Greek and has largely replaced the older name Saos, which some maps still use; Saos is said to come from Saon, the island's first settler, a son of Zeus and a nymph or of Hermes and Rhene. Local legend holds that anyone standing on the summit during the night of a full moon will see a wish come true.

The most used trail to the top starts from the village of Therma on the northern side of the island and passes through forested sections before reaching open rock. Sturdy footwear and enough water are important, as the upper part of the route offers no shade.

Two plant species found on the mountain's slopes grow nowhere else in the world: Polygonum icaricum and Symphyandra samothracica, a type of bellflower native only to this island. The ten gorges that cross the slopes create the shaded and wet conditions that allow these species to survive.