The stupa was built in the 18th century by Lama Ngawang Lodrö, the nephew of Shabdrung Ngawang Namgyal in order to subdue a harmful demon believed to have been living at the site where the chorten is now located. The stupa is modeled after the famous Boudhanath stupa in Nepal popularly known as Jarung Khashor.

Chorten Kora took twelve years to construct and was consecrated by Je Yonten Thaye. The demon that had harmed the people of the valley was apparently subdued and banished. Thereafter, it is said that the people of the valley continue to live in peace and harmony.

source: https://en.wikipedia.org/wiki/Chorten_Kora