Borsh Castle, Medieval castle ruins in Borsh, Albania

Borsh Castle is a fortress ruin on a hilltop near the Ionian Sea, with preserved stone walls and multiple gates that define its structure. The site contains several layers of construction, including the remains of a mosque from the Ottoman period.

The fortress was first documented in the 13th century under the name Sopotos and served as a key defense post for multiple rulers. It changed hands between Byzantine, Epirote, and Ottoman powers before eventually being abandoned.

The ruined Hajji Bendo Mosque, the only standing building inside the walls, was built by Hajji Bendo Vasili, a vassal of Ali Pasha of Yanina, and is considered the only preserved mosque on the Albanian coast. The castle hill is called Sopot, a Slavic name; medieval Greek documents call the castle Sopoton or Sopotos and its harbour Gazopolis.

The road up to the castle is paved with asphalt, so the site can be reached easily by car. The hill of Sopot rises about 500 m above sea level north of Borsh village, west of Fterrë. From the walls, the winding road toward Fterrë is visible below.

The only standing building inside the walls is the ruined Hajji Bendo Mosque, built by Ali Pasha's local ally Haxhi Bendo Vasili. It is described as the only preserved mosque on the Albanian coast, though its roof has collapsed.