Coordinates: 42°0′45″N 27°36′31″E / 42.01250°N 27.60861°E / 42.01250; 27.60861
Strandzha (Bulgarian: Странджа, also transliterated as Strandja; Turkish: Istranca or Yıldız) is a mountain massif in southeastern Bulgaria and the European part of Turkey, in the southeastern part of the Balkans between the plains of Thrace to the west, the lowlands near Burgas to the north and the Black Sea to the east. Its highest peak is Mahya Dağı (Bulgarian: Махиада, Mahiada) (1,031 m or 3,383 ft) in Turkey, while the highest point on Bulgarian territory is Golyamo Gradishte (Bulgarian: Голямо Градище) (710 m or 2,329 ft). The total area of the massif is approximately 10,000 km2 (3,861 sq mi). The name of the massif allegedly derives from Istranca, the former name of the Municipality of Binkılıç in Çatalca district, Istanbul province.
The climate of the area is considerably influenced by the Black Sea and is predominantly humid continental in the mountains and humid subtropical at the coast. Major rivers in the area are the Veleka (147 km or 91 mi long) and the border river Rezovska (112 km or 70 mi long).
"Strandzha" was an revolutionary organization of immigrants from Eastern Thrace to Bulgaria, which existed from 1896 to 1900. It was founded as a legal organization in 1896 in Varna by immigrants led by Petko Kiryakov. Only two months later in December 1896 in Burgas was convened the Congress of the Thracian emigration in the country. Following a first Congress now united company "Strandzha", various initiatives taken place and received public recognition. To perform its task a secret revolutionary committee was founded. This subsidiary body had the task to support the organization and to send armed bands in Thrace. Once, in the next few years it sent several detachments in Strandzha and the Rhodopes. In 1899 the Supreme Macedonian Committee made to "Strandzha" the proposal for unification. This act was realized on the seventh Congress of Supreme Macedonian Committee (30 July-5 August 1900). The combined organization was called the Supreme Macedonian-Adrianople Committee.