A stupa is a mound-like structure containing Buddhist relics, typically the remains of Buddha, used by Buddhists as a place of worship. The stupa is the oldest Buddhist religious monument and was originally only a simple mound of mud or clay to cover supposed relics of the Buddha (cetiya). After the parinirvana of the Buddha, his remains were cremated and the ashes divided and buried under eight stupas with two further stupas encasing the urn and the embers. Little is known about these early stupas, particularly since it has not been possible to identify the original ten monuments. However, some later stupas, such as at Sarnath and Sanchi, seem to be embellishments of earlier mounds.
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.

There are eight different kinds of stupas in Tibetan Buddhism, each referring to major events in the Buddha's life.
Lotus Blossom Stupa
Also known as Stupa of Heaped Lotuses or Birth of the Sugata Stupa, this stupa refers to the birth of the Buddha. "At birth Buddha took seven steps in each of the four directions" (East, South, West and North). In each direction lotuses sprang, symbolizing the Four Immeasurables: love, compassion, joy and equanimity. The four steps of the basis of this stupa is circular, and it is decorated with lotus-petal designs. Occasionally, seven heaped lotus steps are constructed. These refer to the seven first steps of the Buddha.

Enlightenment Stupa
Also known as the Stupa of the Conquest of Mara. This stupa symbolizes the 35-year-old Buddha's attainment of enlightenment under the bodhi tree in Bodh Gaya, where he conquered worldly temptations and attacks manifesting in the form of Mara.

Stupa of Many Doors
Also known as the Stupa of Many Gates. After reaching enlightenment, the Buddha taught his first students in a deer-park near Sarnath. The series of doors on each side of the steps represent the first teachings: the Four Noble Truths, the Six Perfections, the Noble Eightfold Path and the Twelve Links in the Chain of Dependent Origination.

Stupa of Descent from the God Realm
At 42 years old, Buddha spent a summer retreat in Tushita Heaven, where his mother had taken rebirth. In order to repay her kindness he taught the dharma to her reincarnation. Local inhabitants built a stupa like this in Sankasya in order to commemorate this event. This stupa is characterized by having a central projection at each side containing a triple ladder or steps.

Stupa of Great Miracles
Also known as Stupa of Conquest of the Tirthikas. This stupa refers to various miracles performed by the Buddha when he was 50 years old. Legend claims that he overpowered maras and heretics by engaging them in intellectual arguments and also by performing miracles. This stupa was raised by the Lichavi kingdom to commemorate the event.

Stupa of Reconciliation
This stupa commemorates the Buddha's resolution of a dispute among the sangha. A stupa in this design was built in the kingdom of Magadha, where the reconciliation occurred. It has four octagonal steps with equal sides.

Stupa of Complete Victory
This stupa commemorates Buddha's successful prolonging of his life by three months. It has only three steps, which are circular and unadorned.

Stupa of Nirvana
This stupa refers to the death of the Buddha, when he was 80 years old. It symbolizes the Buddha's complete absorption into the highest state of mind. It is bell-shaped and usually not ornamented.

Inside The Stupa

All stupas contain a treasury filled with various objects. Small offerings called Tsa-Tsas fill a major part of the treasury. Creation of various types of Tsa-Tsas is a ceremony itself. Mantras written on paper are rolled into thin rolls, and put into these small clay stupas. Filling the treasury, one layer of Tsa-Tsas are placed, and the empty space between is filled with dry sand. On the new surface appearing, another layer is made, until the entire space of a treasury is full.

The number of Tsa-Tsas are dependent on the size of both the treasury and Tsa-Tsa, since it should be completely filled. For example, the Kalachakra stupa in southern Spain has approximately 14 000 Tsa-Tsas within.
Jewellery and other "precious" objects are also placed in the treasury. It is not necessary that the jewellery be expensive, since it is the symbolic value that is important, not the market price. It is believed that the more objects placed into the stupa, the stronger the energy of the Stupa will be