Prioksko-Terrasny State Nature Biosphere Reserve is a Russian state conservation and research institution in Serpukhov, Moscow Region. One of the country’s oldest and smallest nature reserves, it protects a distinctive area of forests, wetlands and steppe vegetation on terraces along the left bank of the Oka River, about 100 kilometres from Moscow’s Red Square. Its territory is home to 913 species of vascular plants, 153 bird species and 57 wild mammal species.

The reserve is especially known for its Central Bison Nursery, established through the work of scientist Mikhail Zablotsky. The nursery helped prevent the European bison from disappearing and remains a major attraction. Visitors can join guided tours of the nursery throughout the year. During warmer months, they can also explore the Tree-House Park and the Through the Foliage trail.

The reserve offers visitor information and excursion services, and invites people to support conservation by adopting a bison or volunteering.