Lanna Temples originally were built round the chedi (stupas), which contain valuable relics of pious kings and monks. Like solid rocks in a sea of change, the old chedis mark the sites of former temples and are almost the only temple structures that go back to the 13th-15th centuries.
Perhaps their continued existence in some unlikely places in the city is no accident. In Brahmanic-Buddhist cosmology, the chedi "stabilizes the earth", fixing a point where heaven and earth meet. They may be likened to the rising sun at dawn, both separating and joining the earth and sky after the darkness of night. Symbolizing the dhamma, they chase away the darkness of ignorance and chaos.
Though many chedi in Chiang Mai have been damaged by thieves who sought the precious relics contained inside, citizens have repaired and protected them. They are worshipped as sacred symbols representing the cosmic body of the Buddha and the law of the dhamma. Their shape differs, however, due to the particular symbolism of the dhamma chosen by the builders.
Chedis in Chiang Mai have two basic forms; the stepped or prasat style, and the bell style. However, from these basic forms many variations in size and shape have appeared, reflecting the wealth of the city over the centuries.
An early example of the prasat style is the Mahapol Chedi at Wat Chamadevi in Lamphun. Later fine examples are those of Wat Pansat near Chang Phuak bus station and Wat Lok Moli west of Chang Phuak gate.