The country's longest (4,000 metres) and deepest (245 metres) cave, Istvánlápa, is located in the park. Bükk National Park also contains ninety species of nesting birds, some considered endangered.
Istvánlápa, the country's longest (4,000 meters) and deepest (245 meters) cave, resides within Bükk National Park. The park also houses ninety species of nesting birds, some of which are considered endangered.