It has been 30 years since the declaration of the Strandzha Nature Park. The park was declared in 1995 with the aim of preserving the unique nature and sustainable development of the mountain in the area of the Veleka and the Rezovska rivers.

With its 116 054 ha, Strandzha Nature Park is the largest protected area in Bulgaria, and is over 1% of the country's territory. At the same time, the protected area is also one of the most interesting and richest in terms of biological diversity, preserving not only unique ecosystems and biodiversity, but also preserving the original Strandzha folklore, culture, and historical heritage.

The park is of European importance due to the wealth of higher flora, reptiles and nesting birds and of global importance in terms of the protection of mammals, invertebrates, and forests with tertiary vegetation.

The oldest for Bulgaria and continental Europe Tertiary Strandzha forests are categorized into their own subbiome "broad-leaved deciduous forests of the temperate climate with laurel undergrowth" with a clearly distinguishable appearance. The evergreen undergrowth of laurel shrubs in the Eastern beech forests is typical of the South Euxine vegetation and is unique for Bulgaria.

The unique combination of the relict South Euxine vegetation of the Tertiary type with transitional Mediterranean, Pontic, and Central European species and plant communities determines the global scientific and conservation importance of the Strandzha vegetation.

Almost the entire territory of Strandzha Nature Park is a refuge for relict species and communities from past geological times. 64 relict species are found in Strandzha, and for seven of them the mountain is the only refuge on the territory of the European continent. These include the Rhododendron ponticum, the Daphne pontica, the Vaccinium arctostaphylos, the Quercus hartwissiana, the Ilex colchica, the Veronica turrilliana, and Epimedium pubigerum.

The Bulgarian endemics in the park are represented by six species and three subspecies – the Pyrus bulgarica, the Oenanthe millefolia, the Galium bulgaricum, the Veronica krumovii, and local to Strandzha Mountain are the Veronica turrilliana and the Anthemis jordanovii. The second largest bird migration route in Europe passes over Strandzha – Via Pontica. Two-hundred-sixty-nine species of birds have been recorded within the park, which represents two thirds of the entire Bulgarian avifauna. The globally endangered meadow warbler nests in the park, and for the Southern white-backed woodpecker the centuries-old forests of Strandzha are one of the most important habitats. The populations of the half-white-necked flycatcher, the great olive mockingbird and the mourning tit are of global importance, and of European importance – the Egyptian vulture, the black and white stork, the owl and four species of eagles.

There are 5 strict reserves within the park. Among them is the oldest in Bulgaria – “Silkosia”, which occupies its place of honor as the first site to receive legal protection in the country. It is the declaration of the reserve in 1933 that is considered the beginning of nature conservation activities in our country. With the declaration of Silkosia, as well as other protected areas, such as the Parangalitsa, Bayuvi-Djindzhiritsa, and Vitosha Nature Park reserves in the early 1930s, the foundations of the network of protected areas in Bulgaria were laid, which have served as models for the preservation of the unique Bulgarian nature and have largely contributed to its long-term conservation.

In 2017, a large part of the nature park was declared as the Uzunbodzhak Biosphere Park under the UNESCO Man and the Biosphere Program, thus providing an opportunity to achieve balanced and sustainable economic development for the region, based on clean and preserved nature, as well as the production and supply of local products and regional brands with high added value.