bSam-yas is considered as the oldest Buddhist monastery in Tibet, built by King Khri-srong lde-btsan at the end of the Vlllth century. The Records of the Tang dynasty do not mention the monastery and there are but a very few references to it in the ancient Tibetan sources before Xllth century. The basic figure of the plan is the square : the central temple being included in a square divided into nine, and both the plan and the elevation are organized on the base of number three and multiples. The central temple is three stories high, square shaped and surrounded by two cross-shaped buildings. The monastery, including twelve minor temples and various buildings, is enclosed within a circular wall. bSam-yas is traditionaly considered as a mandala, and as a representation of the Sumeru. The architectural model is often proposed as Indian, but square and cross-shaped patterns existed in Tibet before the coming of Buddhism and Indian influence. Plans found as far as Iran or China can be compared with those of the mandala and of bSam-yas.
