The source of book carriers is located on the edge of Liepkalnis forest, in Vilkai village. The name relates to the importance of this place in the period of bookbinding. The spring and the chapel pillar next to it were excellent landmarks for book carriers to the nearby homestead of book carriers’ patrons: to cuddle up for rest, to hide books. The area of the natural heritage object is 0.145 ha. Spring water is clean, clear, odorless, cold (about +8 ºC), fresh, low in minerals, iron. People believed in the healing properties of spring water; it was mainly used to treat eye diseases. Next to the source is a chapel pillar that was built during Soviet era in 1983 instead of the former chapel pillar, which was popular with book carriers.