which was heated and held services all year long. It was reconstructed several times in 1720–1749 and in 1764 rebuilt into its present 9-dome design. In 1714, the 22-dome Transfiguration Church () was constructed and soon after the bell tower was added, thereby completing the Kizhi Pogost. The bell tower was entirely rebuilt in 1862. Much earlier, some time in the 17th century, a long fence was built around the churches, which then served as a protection ground against Swedish and Polish incursions. Kizhi churches were built on stones, without a deep foundation. Their major basic structural unit is a round log of Scots pine (Pinus sylvestris) about in diameter and long. Many thousands logs were brought for construction from the mainland which was a complex logistical task at that time. The logs were cut and shaped with axes and assembled without nails, using interlocking corner joinery — either round notch or dovetail. Flat roofs were made of spruce planks and the domes are covered in aspen. Kizhi museum Open-air museum Kizhi is one of the first in Russia, which started functioning on the island in 1951 and currently contains about 87 wooden constructions. The most famous of them is the Kizhi Pogost, which contains two churches and a bell tower surrounded by a fence. The pogost was included in the UNESCO World Heritage list in 1990. Since 1951, a large number of historical buildings were moved to the island. They include Church of the Resurrection of Lazarus from Murom Monastery, which is regarded as the oldest remaining wooden church in Russia (second half of the 14th century), several bell towers, more than 20 peasant houses, mills, barns and saunas. In 1993, the museum was included into a short list a Russian Cultural Heritage sites. The museum contains more than 41,000 exhibits. Most of them are domestic artifacts: tools, dishes, utensils, furniture, etc. There are about 1000 icons of the 16th–19th centuries which includes Russia's only collection of "heavens". There are also church items, such as crosses early manuscript of 17th–19th centuries. The museum also contains exhibits of the 20th century, about 10,000 photographs and 1,500 drawings. The museum conducts a wide range of scientific studies in the history, archeology, ecology, nature and other fields related to the island. It is based in Kizhi and Petrozavodsk, has an advanced web portal and a web camera on the island. Kizhi museum