Ku Chang is an ancient monument believed to be the stupa enshrining the remains of "Pu Kam Nga Khiao" (The Black Elephant with Green Tusks), the powerful state elephant of Queen Jamadevi, the first ruler of Hariphunchai. According to legend, this elephant possessed immense spiritual power; its green tusks could weaken any enemy they pointed toward. After its death, Queen Jamadevi commissioned a unique bell-shaped stupa to house its remains, positioned to face north to protect the city. Today, it is revered as "Chao Pho Ku Pu Chang," a guardian spirit of Lamphun. Locals frequently visit to pray for success, victory, and protection from harm.