Uzunbodzhak (Bulgarian: Узунбоджак), also transliterated as Ouzounboudjak is an UNESCO Biosphere Reserve, one of the five nature reserves in Strandzha Nature Park in south-eastern Bulgaria. The reserve is sometimes called Lopushna (Bulgarian: Лопушна). Uzunbodzhak was established on 13 December 1956 and was included in the UNESCO network of biosphere reserves in March 1977. It covers an area of 2529.6 hectares, or 25.296 km2. All economic activities are prohibited on the territory of the reserve.