Approximately 40 kilometers (25 mi) northwest of Yogyakarta, Borobudur is located in an elevated area between two twin volcanoes, Sundoro-Sumbing and Merbabu-Merapi, and two rivers, the Progo and the Elo. According to local myth, the area known as Kedu Plain is a Javanese 'sacred' place and has been dubbed 'the garden of Java' due to its high agricultural fertility. Besides Borobudur, there are other Buddhist and Hindu temples in the area, including the Prambanan temples compound. During the restoration in the early 20th century, it was discovered that three Buddhist temples in the region, Borobudur, Pawon and Mendut, are lined in one straight line position. It might be accidental, but the temples' alignment is in conjunction with a native folk tale that a long time ago, there was a brick-paved road from Borobudur to Mendut with walls on both sides. The three temples (Borobudur–Pawon–Mendut) have similar architecture and ornamentation derived from the same time period, which suggests that ritual relationship between the three temples, in order to have formed a sacred unity, must have existed, although exact ritual process is yet unknown.

Unlike other temples, which were built on a flat surface, Borobudur was built on a bedrock hill, 265 m (869 ft) above sea level and 15 m (49 ft) above the floor of the dried-out paleolake. The lake's existence was the subject of intense discussion among archaeologists in the 20th century; Borobudur was thought to have been built on a lake shore or even floated on a lake. In 1931, a Dutch artist and a scholar of Hindu and Buddhist architecture, W.O.J. Nieuwenkamp, developed a theory that Kedu Plain was once a lake and Borobudur initially represented a lotus flower floating on the lake. Lotus flowers are found in almost every Buddhist work of art, often serving as a throne for buddhas and base for stupas. The architecture of Borobudur itself suggests a lotus depiction, in which Buddha postures in Borobudur symbolize the Lotus Sutra, mostly found in many Mahayana Buddhism (a school of Buddhism widely spread in the east Asia region) texts. Three circular platforms on the top are also thought to represent a lotus leaf. Nieuwenkamp's theory, however, was contested by many archaeologists because the natural environment surrounding the monument is a dry land.

Geologists, on the other hand, support Nieuwenkamp's view, pointing out clay sediments found near the site. A study of stratigraphy, sediment and pollen samples conducted in 2000 supports the existence of a paleolake environment near Borobudur, which tends to confirm Nieuwenkamp's theory. The lake area fluctuated with time and the study also proves that Borobudur was near the lake shore c. 13th and 14th centuries. River flows and volcanic activities shape the surrounding landscape, including the lake. One of the most active volcanoes in Indonesia, Mount Merapi, is in the direct vicinity of Borobudur and has been very active since the Pleistocene.

There is no written record of who built Borobudur or of its intended purpose. The construction time has been estimated by comparison between carved reliefs on the temple's hidden foot and the inscriptions commonly used in royal charters during the 8th and 9th centuries. Borobudur was likely founded around 800 AD. This corresponds to the period between 760 and 830 AD, the peak of the Sailendra dynasty in central Java,when it was under the influence of the Srivijayan Empire. The construction has been estimated to have taken 75 years and been completed during the reign of Samaratungga in 825.

There is confusion between Hindu and Buddhist rulers in Java around that time. The Sailendras were known as ardent followers of Lord Buddha, though stone inscriptions found at Sojomerto suggest they may have been Hindus. It was during this time that many Hindu and Buddhist monuments were built on the plains and mountain around the Kedu Plain. The Buddhist monuments, including Borobudur, were erected around the same time as the Hindu Shiva Prambanan temple compound. In 732 AD, the Shivaite King Sanjaya commissioned a Shivalinga sanctuary to be built on the Ukir hill, only 10 km (6.2 miles) east of Borobudur.

Construction of Buddhist temples, including Borobudur, at that time was possible because Sanjaya's immediate successor, Rakai Panangkaran, granted his permission to the Buddhist followers to build such temples. In fact, to show his respect, Panangkaran gave the village of Kalasan to the Buddhist community, as is written in the Kalasan Charter dated 778 AD. This has led some archaeologists to believe that there was never serious conflict concerning religion in Java as it was possible for a Hindu king to patronize the establishment of a Buddhist monument; or for a Buddhist king to act likewise. However, it is likely that there were two rival royal dynasties in Java at the time—the Buddhist Sailendra and the Saivite Sanjaya—in which the latter triumphed over their rival in the 856 battle on the Ratubaka plateau. This confusion also exists regarding the Lara Jonggrang temple at the Prambanan complex, which was believed that it was erected by the victor Rakai Pikatan as the Sanjaya dynasty's reply to Borobudur, but others suggest that there was a climate of peaceful coexistence where Sailendra involvement exists in Lara Jonggrang.

In two months, Cornelius and his 200 men cut down trees, burned down vegetation and dug away the earth to reveal the monument. Due to the danger of collapse, he could not unearth all galleries. He reported his findings to Raffles including various drawings. Although the discovery is only mentioned by a few sentences, Raffles has been credited with the monument's recovery, as one who had brought it to the world's attention.

Hartmann, a Dutch administrator of the Kedu region, continued Cornelius' work and in 1835 the whole complex was finally unearthed. His interest in Borobudur was more personal than official. Hartmann did not write any reports of his activities; in particular, the alleged story that he discovered the large statue of Buddha in the main stupa.In 1842, Hartmann investigated the main dome although what he discovered remains unknown as the main stupa remains empty.

The Dutch East Indies government then commissioned F.C. Wilsen, a Dutch engineering official, who studied the monument and drew hundreds of relief sketches. J.F.G. Brumund was also appointed to make a detailed study of the monument, which was completed in 1859. The government intended to publish an article based on Brumund study supplemented by Wilsen's drawings, but Brumund refused to cooperate.

 

The government then commissioned another scholar, C. Leemans, who compiled a monograph based on Brumund's and Wilsen's sources. In 1873, the first monograph of the detailed study of Borobudur was published, followed by its French translation a year later. The first photograph of the monument was taken in 1873 by a Dutch-Flemish engraver, Isidore van Kinsbergen.

Following the major 1973 renovation funded by UNESCO,Borobudur is once again used as a place of worship and pilgrimage. Once a year, during the full moon in May or June, Buddhists in Indonesia observe Vesak (Indonesian: Waisak) day commemorating the birth, death, and the time when Siddhārtha Gautama attained the highest wisdom to become the Buddha Shakyamuni. Vesak is an official national holiday in Indonesia and the ceremony is centered at the three Buddhist temples by walking from Mendut to Pawon and ending at Borobudur.

The monument is the single most visited tourist attraction in Indonesia. In 1974, 260,000 tourists of whom 36,000 were foreigners visited the monument.The figure hiked into 2.5 million visitors annually (80% were domestic tourists) in the mid 1990s, before the country's economy crisis. Tourism development, however, has been criticized for not including the local community on which occasional local conflict has arisen.In 2003, residents and small businesses around Borobudur organized several meetings and poetry protests, objecting to a provincial government plan to build a three-story mall complex, dubbed the 'Java World'.

On 21 January 1985, nine stupas were badly damaged by nine bombs. In 1991, a blind Muslim preacher, Husein Ali Al Habsyie, was sentenced to life imprisonment for masterminding a series of bombings in the mid 1980s including the temple attack. Two other members of a right-wing extremist group that carried out the bombings were each sentenced to 20 years in 1986 and another man received a 13-year prison term. On 27 May 2006, an earthquake of 6.2 magnitude on the Richter scale struck the south coast of Central Java. The event had caused severe damage around the region and casualties to the nearby city of Yogyakarta, but Borobudur remained intact.

On 28 August 2006 the Trail of Civilizations symposium was held in Borobudur under the auspices of the governor of Central Java and the Indonesian Ministry of Culture and Tourism, also present the representatives from UNESCO and predominantly Buddhist nations of Southeast Asia, such as Thailand, Myanmar, Laos, Vietnam and Cambodia. Climax of the event was the "Mahakarya Borobudur" ballet performance in front of the temple of Borobudur. It was choreographed to feature traditional Javanese dancing, music and costumes, and tell the history about the construction of the Borobudur. After the symposium, the Mahakarya Borobudur ballet is performed several times, especially during annual national Waisak commemoration at Borobudur attended by Indonesian President.UNESCO identified three specific areas of concern under the present state of conservation: (i) vandalism by visitors; (ii) soil erosion in the south-eastern part of the site; (iii) analysis and restoration of missing elements. The soft soil, the numerous earthquakes and heavy rains lead to the destabilization of the structure. Earthquakes are by far the most contributing factors, since not only stones fall down and arches crumble, but the earth itself can move in waves, further destroying the structure.^[37] The increasing popularity of the stupa brings in many visitors, most of whom are from Indonesia. Despite warning signs on all levels not to touch anything, the regular transmission of warnings over loudspeakers and the presence of guards, vandalism on reliefs and statues is a common occurrence and problem, leading to further deterioration. As of 2009, there is no system in place to limit the number of visitors allowed per day, or to introduce mandatory guided tours only.

Borobudur was heavily affected by the eruption of Mount Merapi in October and November 2010. Volcanic ash from Merapi fell on the temple complex, which is approximately 28 kilometres (17 mi) west-southwest of the crater. A layer of ash up to 2.5 centimetres (1 in) fell on the temple statues during the eruption of 3–5 November, also killing nearby vegetation, with experts fearing that the acidic ash might damage the historic site. The temple complex was closed from 5 to 9 November to clean up the ashfall.

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. 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. 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 prevent flooding, 100 spouts are installed at each corner, each with a unique carved gargoyle in the shape of a giant or makara.

Borobudur differs markedly from the general design of other structures built for this purpose. Instead of being built on a flat surface, Borobudur is built on a natural hill. However, construction technique is similar to other temples in Java. Without the inner spaces seen in other temples, and with a general design similar to the shape of pyramid, Borobudur was first thought more likely to have served as a stupa, instead of a temple.^[42] A stupa is intended as a shrine for the Buddha. Sometimes stupas were built only as devotional symbols of Buddhism. A temple, on the other hand, is used as a house of worship. The meticulous complexity of the monument's design suggests that Borobudur is in fact a temple.

Congregational worship in Borobudur is performed in the form 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 to symbolize Buddhist cosmology.

Little is known about Gunadharma, the architect of the complex. His name is recounted from Javanese folk tales rather than written inscriptions.

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. The unit is thus relative from one individual to the next, 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 the fractal and self-similar geometry in Borobudur's design.This ration was also found in the design of Pawon and Mendhut, Buddhist temples nearby. Archeologists have conjectured that the 4:6:9 ratio and the tala have calendrical, astronomical and cosmological significance, as is the case in the temple of Angkor Wat in Cambodia.