At Žemaičių Kalvarija, the Forest Trail enters the protected area – Žemaitija National Park. The park was established to protect, manage and regulate the use of landscape complexes of national importance and anthropoecosystems representing the natural and cultural peculiarities of the ethnocultural area of Žemaitija. The area of the national park covers 21754 ha. The largest lake in Žemaitija, Plateliai lake, is rich in the underwater world, with fish reminiscent of the ice age - Coregonus lavaretus holsatus, medieval cultural heritage: castle remains, bridge poles. The lake is also distinguished by the abundance of peninsulas, bays and 7 islands. The terrain of the Žemaitija National Park was formed by a glacier about 12,000 years ago. The whole territory of the national park is located in the northwestern part of the Žemaitija Upland and is characterized by a hilly terrain. In this section of the Forest Trail, the winding road from Žemaičių Kalvarija opens the spectacular landscape panoramas, where castle mounds, sacred hills, old cemeteries hidden among the forests, expressive hills and meadows are the old cultural heritage that is an integral part of the Žemaitija National Park. The landscape of the park is diversified by rivers, streams, larger and smaller lakes, swamps, springs.