A stupa is a mound-like or semi-hemispherical structure containing Buddhist relics and artifacts, typically the ashes of the deceased Buddhist monks, used by Buddhists as a place for practicing meditation. “The shape of the stupa represents the Buddha, crowned and sitting in meditation posture on a lion throne. His crown is the top of the spire; his head is the square at the spire's base; his body is the vase shape; his legs are the four steps of the lower terrace; and the base is his throne.”
In the centuries following the Buddha’s mahaparinirvana the new faith underwent rapid expansion and change. By the first century AD, Buddhist teachings had spread throughout the Indian sub-continent, to Afghanistan in the north and Sri Lankan in the south. In the second and third centuries it travelled through Central Asia to China and by the fourth and fifth centuries it had reached Burma, Thailand, Korea and Indonesia, finally arriving in Japan between the sixth and ninth centuries.
Wherever Buddhism went, the Buddha’s relics were enshrined in stupas as objects of veneration. Stupas evolved in many different forms under various names – in Thailand they are called chedis, in Burma and China pagodas and in Tibet chortens. The Swayambunath Stupa in Kathmandu, Nepal, is close to the original type with a hemispherical dome; the eyes painted on the tower probably represent the guardian deities of the four cardinal points, who are said to reside there. At the apex is a spire traditionally this is divided into sections representing the stages on the path to Enlightenment.
Building stupas has always been considered an excellent way to accumulate good karma, so sites such as this are often surrounded by numerous small stupas dedicated by worshippers. These often contain Buddhist texts or the remains of renowned Buddhist teachers. People who cannot afford to build full-scale stupas often dedicate small models or even simply clay plaques stamped with images of stupas. The enormous stupas like Swayambhunath and Boudhanath may contain Buddha statues like Amitabha Buddha, Akshobhaya Buddha, Vairochana Buddha, Ratna Sambhava and Amoghsiddhi Buddha. These Buddhas were the Buddhas of the past and represent Pancha Buddhas, who are Buddha in metaphorical sense.