Photograph of the thunderbolt at Swayambhunath in Nepal. from an album of 30 prints credited to Herzog and Higgins, taken in ca. 1901 and part of the Curzon Collection. Both Buddhism and Hinduism have flourished side by side in Nepal for centuries. Nepalese Buddhism is mostly of the Hinayana and Vajrayana form; the stupa of Swayambhunath is Nepal's most revered Buddhist temple and one of the most sacred Buddhist sites in the world. Tradition believes the stupa to be much older than its 5th century AD founding. A long stairway leads up to the eastern side of the stupa and at its head is a huge copper gilt vajra or thunderbolt, placed on top of a stone mandala (cosmic plan). The vajra was originally an attribute of Indra, the Hindu god of weather and King of the Gods. In Vajrayana or Tantric Buddhism, it has assumed a powerful symbolism, of indestructibility and purity as a diamond and of the flash of intuition or potent awakening of knowledge. It is a frequent motif in Nepalese art.