number may be about eleven." A mid-twentieth-century account reported 37 islands and said that 19 of were the current or former sires of either monasteries or churches. The lake islands were the home of ancient Ethiopian emperors. Treasures of the Ethiopian Church are kept in the isolated island monasteries (including Kebran Gabriel, Ura Kidane Mehret, Narga Selassie, Daga Estifanos, Medhane Alem of Rema, Kota Maryam and Mertola Maryam). The body of Yekuno Amlak is interred in the monastery of St. Stephen on Daga Island; other Emperors whose tombs are on Daga include Dawit I, Zara Yaqob, Za Dengel and Fasilides. Other important islands in Lake Tana include Dek, Mitraha, Gelila Zakarias, Halimun, and Briguida. In the late 20th century, the scholar Paul B. Henze reported being shown a rock on the island of Tana Qirqos and being told it was where the Virgin Mary had rested during her journey back from Egypt. He was also told that Saint Frumentius, the bishop known for introducing Christianity to Ethiopia, was "allegedly buried on Tana Cherqos." Landmarks The Amhara region has the most world heritage sites of any region in Ethiopia and is endowed with natural and geographic wonders and ecosystems. The region contains Ethiopia's largest inland body of water Lake Tana, which is the source of the Blue Nile river. In 2015 Lake Tana was recognized as a UNESCO Biosphere Reserve for its enormous biodiversity, and national and international importance. The Semien Mountains National Park has been designated as the one of the first natural World Heritage Site by UNESCO in the world, and the very first in Africa in the natural criteria since 1978. Chosen for its spectacular landscapes and global significance for biodiversity conservation. Situated within the Semien Mountains, Ethiopia's highest peaks Ras Dashen reaches an elevation of (). The park also has Ethiopia's second and third highest mountains, Kidis Yared () and Mount Bwahit (). The park is home to endangered species found nowhere else in the world, examples of endemic fauna include the iconic walia ibex, the gelada baboon, and the Ethiopian wolf (or Simien fox) among others. The wide range of altitudes has given the country a variety of ecologically distinct areas, leading to the evolution of endemic species in ecological isolation. Amhara region also leads in cultural world heritage sites in Ethiopia, with the Rock Hewn Churches of Lalibela jointly added with Senegal's Gorée island as