The traditional Mongolian dwelling is known as a ''ger''. In the past it was known by the Russian term ''yurt'', but this has been changing as the Mongolian term becomes better known in English-speaking countries. According to Mongolian artist and art critic N. Chultem, the ''ger'' was the basis for development of traditional Mongolian architecture. In the 16th and 17th centuries, lamaseries were built throughout the country. Many of them started as ''ger''-temples. When they needed to be enlarged to accommodate the growing number of worshippers, the Mongolian architects used structures with 6 and 12 angles with pyramidal roofs to approximate to the round shape of a ''ger''. Further enlargement led to a quadratic shape of the temples. The roofs were made in the shape of marquées. The trellis walls, roof poles and layers of felt were replaced by stone, brick, beams and planks, and became permanent.