To the north-east of Kielce are the Świętokrzyskie Mountains. That massif reaching 600 metres is among the oldest in Europe. Even before Christ the locals of the region specialized in iron smelting. In the most beautiful part of the mountains, the Świętokrzyski National Park has been established. The local Benedictine monastery of the Holy Cross preserves five splinters claimed to have originated from the Cross of Christ. The monastery is a well-known pilgrimage site.