Visit the inner chambers of Tallinn's 13th-century St. Catherine's Monastery to learn about the lives of medieval monks. These rooms once included three wings, together called the Klostrom, of which the east wing still survives; It consists of a dormitory for monks, a library, a refectory, former residences and other rooms. Visitors should not miss the mysterious "energy pillar" in the cellar which is believed to be a source of physical and spiritual health.