What's inside Buddhist "burial mounds"?

Pat Macpherson and Dhr. Seven (eds.), Wisdom Quarterly Wiki edit Bimaran casket

The Buddha in gold relief, Bimaran sacred Buddhist reliquary, contents of stupa, Gandhara

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Bodhisattva ("buddha-to-be") with halo relief (Wiki)

What is a stupa? It is a Scythian burial mound found from the Ukraine down through Central Asia and throughout the subcontinent and Buddhist world. The mound contains the relics of the Buddha, and buddhas of the distant past, and chakravartin rulers or "world monarchs." They are stylized as pagodas and mandalas representing the world system or cosmos. Inside, they contain gems, gold, ashes and relics  or cremation remains (shariras), jewelry, and other precious artifacts like time capsules -- coins, carvings, inscriptions, and the physical remains of great supremely enlightened teachers. There are tens of thousands in the world, but the eight greatest contain the primary relics of Shakyamuni, "Sage of the Scythians," as well as those in the largest unexcavated Buddhist monastic complex at Mes Aynak, Gandhara (now Afghanistan) and the largest excavated Buddhist temple pyramid at Borobudur, Java, Indonesia. These are the contents of the Bimaran stupa, which contained the gold Bimaran casket or reliquary.

The Stupa Nb.2 at Bimaran, where the sacred Buddhist reliquary gold casket was excavated. Drawing by Charles Masson (Ariana Antiqua: A Descriptive Account of the Antiquities and Coins of Afghanistan, Horace Hayman Wilson, Charles Masson, East India Company, 1841).