Golestan National Park, east of Gonbad-e Kavus, is one of the oldest and largest protected areas in Iran — 90,000 hectares of deciduous Hyrcanian forest along the southern slope of the eastern Alborz mountains. The park has been on the UNESCO World Heritage list since 2019 as part of the Hyrcanian Forests inscription, and it shelters Persian leopards, brown bears, wild boar, and one of the larger remaining populations of Caspian red deer.
Wildlife is difficult to see — the forest is dense and the animals are wary — but the landscapes are reward enough. Trails into the park leave from the small towns of Tangrah and Robat Qarah Bil, and a permit from the park office is required. Spring and autumn are the best seasons; summer is hot, and winter access can be blocked by snow.