The Butter Sculpture Hall (Suyouhua Yuan) is the most technically extraordinary building in the Kumbum complex, housing examples of the ancient Tibetan art of yak-butter sculpture that the monastery's monks have practised for centuries. The works range from small ritual objects to large-scale multi-figure narratives, and the skill involved — creating detailed three-dimensional forms from a material that must be worked cold (monks often submerge their hands in ice water to keep the butter firm) — is remarkable.
The best time to see the most ambitious works is during the Butter Festival (first month of the Tibetan lunar calendar, usually February or early March), when the year's new creations are displayed for a single night before being ceremonially dismantled. At other times of year, permanent display pieces and smaller ritual sculptures are on view. Photography policies vary; check locally.