Although their form has evolved over the centuries, the basic principles of structure have remained unchanged. The simple arrangement of lattice walls, rafters and hub, insulated and clad with felt, are still exhibited today in Mongolia, Kyrgyzstan, Kazakstan, Uzbekestan, Tajikistan, Pakistan and North-Eastern China.
The steppes of Mongolia are a vast expanse of open grassland where yurts are the ideal dwelling for nomadic pastoralists. The climate of the continental interior is extreme with winter temperatures touching on Siberian, summer highs like the Gobi desert and frequent high winds rolling off the mountains. The yurt's circular form, felted cladding and ease of transportation has been the preferred vernacular architectural form for millennia, a balanced human response to constructing dwellings using local materials which meet the needs of local conditions.
Early yurts exhibited a higher, bottle-shaped roof structure, which normally had an opening in the centre to allow light in and let smoke out. This tono was also the spiritual centre of the yurt, linking the earthly and celestial realms. To the Mongols the construction is a representation of the universe. The roof is the heavens, the hub the sun and gateway to the celestial realm and the lattice walls (bagana) the world tree, the way of ascension. A Mongolian shaman will journey to other realms through the tono. Opposite the north-facing door is the khoimor, the most sacred part of the yurt where esteemed objects are kept and honoured guests are seated. There is often a shrine to religious icons. The hearth contains the five basic elements of fire, earth, wood, metal and water.
The Mongolian ger was often permanently mounted on a cart, pulled by oxen. During the reign of Ghengis Khan (1162 - 1227 AD) the entire Mongol empire was administered from a ger cart.
The orientation of a Mongolian ger traditionally placed the door facing south, to evade the prevailing northerly winds and help draw smoke through the open tono. A by-product of this orientation is the sun entering through the open door casts an illuminated beam onto the roof spokes akin to a sundial, by which any Mongol can tell the time. The layout follows tradition - with a men's side, women's side and sacred area. Even today 75% of Mongols live in yurts, which literally translated means 'home'.