Resting on a hillock 3 km west of Kathmandu, Swayambhu (Swayambhunath in Tibetan) is one of the holiest Buddhist stupas in Nepal. It is said to have evolved spontaneously when the valley was created out of a primordial lake more than 2,000 years ago. This stupa is the oldest of its kind in Nepal and has numerous shrines and monasteries on its premises. The stupa has stood as a hallmark of faith and harmony for centuries with Hindu temples and deities incorporated in this Buddhist site. The glory of Kathmandu Valley is said to have started from this point.
The Earth is my witness and the monkeys too Buddha
Swayambhu is among the oldest religious sites in Nepal. According to the Gopālarājavaṃśāvalī, it was founded by the great-grandfather of King Mānadeva (464–505 CE), King Vṛsadeva, about the beginning of the fifth century CE. This seems to be confirmed by a damaged stone inscription found at the site, which indicates that King Vrsadeva ordered work done in 640 CE.
However, Emperor Ashoka is said to have visited the site in the third century BCE and built a temple on the hill which was later destroyed.