In the temple grounds of Wat Chedi Luang is the city pillar (Lak Mueang) of Chiang Mai, named Sao Inthakin. It was moved to this location in 1800 by King Chao Kawila; it was originally located in Wat Sadeu Muang. He also planted three dipterocarp trees there, which are supposed to assist the city pillar to protect the town. A festival in honor of the city pillar is held every year in May and lasts 6–8 days.

Source: Wikipedia