The Shumen Plateau is an interesting geomorphological formation in the eastern part of the Danube hilly plain, formed as a result of interaction between internal and external earth forces on chalk materials. Its slopes are steep and in places the upper part ends in picturesque rock wreaths. The relief of the park features three main parts: the area of Ilchov Bair; a ridge in the eastern part; and an extensive slope - the area of Kyoshkovete. The average altitude is 350 m and the highest point, 502 m, is in the Tarnov Tabia area. Limestones, sandstones and marls make up the Shumen Plateau, which has allowed the natural elements to form bizarre shapes on the surface and below. There are about 60 caves in the park area. The largest is the Bisserna Cave - a two-storey cave about 2.6 km long. In the Middle Ages, some of the caves were converted into rock cells, churches, and monasteries.