Inthakin Festival
Inthakhin is an annual festival held in Chiang Mai to celebrate the worship of the grand city pillar as well as the giving of offerings.
The pillar was first constructed by King Mangrai in 1296 following the foundation of the city and was later moved to its current location inside a shrine in 1800.
source: https://www.chiangmaitravelhub.com/events/inthakin-festival/