According to Buddhist scriptures, after Lord Buddha passed away in Kushinagar, his body was cremated with full honors at the site where the Rambhar Stupa now stands. The Mallas of Kushinagar, who were his followers, performed the last rites. The original stupa is believed to have been built shortly after the cremation to enshrine the relics of the Buddha. Over the centuries, the stupa underwent several renovations and expansions. Archaeological excavations have revealed evidence of different construction phases, indicating the site's continuous importance as a pilgrimage center. Today's structure largely dates back to the Gupta period, showcasing the architectural styles prevalent during that era and reflecting the enduring reverence for the Buddha's legacy.