ARCHITECTURE

Borobudur is built as a single large stupa, and when viewed from above takes the form of a giant tantric Buddhist mandala, simultaneously representing the Buddhist cosmology and the nature of mind.[35] The foundation is a square, approximately 118 meters (387 ft) on each side. It has nine platforms, of which the lower six are square and the upper three are circular. The upper platform features seventy-two small stupas surrounding one large central stupa. Each stupa is bell-shaped and pierced by numerous decorative openings. Statues of the Buddha sit inside the pierced enclosures.
Approximately 55,000 cubic metres (72,000 cu yd) of stones were taken from neighbouring rivers to build the monument.[36] The stone was cut to size, transported to the site and laid without mortar. Knobs, indentations and dovetails were used to form joints between stones. Reliefs were created in-situ after the building had been completed. The monument is equipped with a good drainage system to cater for the area's high stormwater run-off. To avoid inundation, 100 spouts are provided at each corner with a unique carved gargoyles in the shape of giants or makaras.

Half cross-section with 4:6:9 height ratio for foot, body and head, respectively.
Borobudur differs markedly with the general design of other structures built for this purpose. Instead of building on a flat surface, Borobudur is built on a natural hill. The building technique is, however, similar to other temples in Java. With no inner space as in other temples and its general design similar to the shape of pyramid, Borobudur was first thought more likely to have served as a stupa, instead of a temple.[36] A stupa is intended as a shrine for the Lord Buddha. Sometimes stupas were built only as devotional symbols of Buddhism. A temple, on the other hand, is used as a house of deity and has inner spaces for worship. The complexity of the monument's meticulous design suggests Borobudur is in fact a temple. Congregational worship in Borobudur is performed by means of pilgrimage. Pilgrims were guided by the system of staircases and corridors ascending to the top platform. Each platform represents one stage of enlightenment. The path that guides pilgrims was designed with the symbolism of sacred knowledge according to the Buddhist cosmology.[37]

A narrow corridor with reliefs on the wall.
Little is known about the architect Gunadharma.[38] His name is actually recounted from Javanese legendary folk tales rather than written in old inscriptions. He was said to be one who "... bears the measuring rod, knows division and thinks himself composed of parts."[38] The basic unit measurement he used during the construction was called tala, defined as the length of a human face from the forehead's hairline to the tip of the chin or the distance from the tip of the thumb to the tip of the middle finger when both fingers are stretched at their maximum distance.[39] The unit metrics is then obviously relative between persons, but the monument has exact measurements. A survey conducted in 1977 revealed frequent findings of a ratio of 4:6:9 around the monument. The architect had used the formula to lay out the precise dimensions of Borobudur.[39] The identical ratio formula was further found in the nearby Buddhist temples of Pawon and Mendhut. Archeologists conjectured the purpose of the ratio formula and the tala dimension has calendrical, astronomical and cosmological themes, as of the case in other Hindu and Buddhist temple of Angkor Wat in Cambodia.[38]

A carved gargoyle-shaped water spout for water drainage.
The main vertical structure can be divided into three groups: base (or foot), body, and top, which resembles the three major division of a human body.[38] The base is a 123x123 m (403.5x403.5 ft) square in size and 4 meters (13 ft) high of walls.[36] The body is composed of five square platforms each with diminishing heights. The first terrace is set back 7 meters (23 ft) from the edge of the base. The other terraces are set back by 2 meters (7 ft), leaving a narrow corridor at each stage. The top consists of 3 circular platforms, with each stage supporting a row of perforated stupas, arranged in concentric circles. There is one main dome at the center; the top of which is the highest point of the monument (35 meters (115 ft) above ground level). Access to the upper part is through stairways at the centre of each side with a number of gates, watched by a total of 32 lion statues. The main entrance is at the eastern side, the location of the first narrative reliefs. On the slopes of the hill, there are also stairways linking the monument to the low-lying plain.
The monument's three divisions symbolize three stages of mental preparation towards the ultimate goal according to the Buddhist cosmology, namely Kāmadhātu (the world of desires), Rupadhatu (the world of forms), and finally Arupadhatu (the formless world).[40] Kāmadhātu is represented by the base, Rupadhatu by the five square platforms (the body), and Arupadhatu by the three circular platforms and the large topmost stupa. The architectural features between three stages have metaphorical differences. For instance, square and detailed decorations in the Rupadhatu disappear into plain circular platforms in the Arupadhatu to represent how the world of forms – where men are still attached with forms and names – changes into the world of the formless.[41]
In 1885, a hidden structure under the base was accidentally discovered.[42] The "hidden foot" contains reliefs, 160 of which are narrative describing the real Kāmadhātu. The remaining reliefs are panels with short inscriptions that apparently describe instruction for the sculptors, illustrating the scene to be carved.[43] The real base is hidden by an encasement base, the purpose of which remains a mystery. It was first thought that the real base had to be covered to prevent a disastrous subsidence of the monument through the hill.[43] There is another theory that the encasement base was added because the original hidden foot was incorrectly designed, according to Vastu Shastra, the Indian ancient book about architecture and town planning.[42] Regardless of its intention, the encasement base was built with detailed and meticulous design with aesthetics and religious compensation.