Construction began in 1961 under the direction of President Sukarno. Monas was opened to the public in 1975. It is topped by a flame covered with gold foil. The monument and the museum are open daily from 08.00 - 15.00 Western Indonesia Time throughout the week except for the last Monday of each month when the monument is closed.
After the Indonesian government returned to Jakarta from Yogyakarta in 1950 following the Dutch recognition of Indonesian independence, President Sukarno began to contemplate the construction of a national monument comparable to the Eiffel Tower on the square in front of the Presidential Palace. On 17 August 1954, a National Monument Committee was established and a design competition was held in 1955. This attracted 51 entries, but only one design, by Frederich Silaban, met any of the criteria determined by the committee, which included reflecting the character of Indonesia in a building capable of lasting for centuries. A repeat competition was held in 1960, but once again, none of the 136 entries met the criteria. The chairman of the jury team then asked Silaban to show his design to Sukarno. However, Sukarno didn't like the design as he wanted the monument to be in the form of a linga and yoni. Silaban was asked to design such a monument, but his design was for a monument so large that it would have been unaffordable given the economic conditions at the time. Silaban refused to design a smaller monument, suggesting that construction be delayed until the Indonesian economy improved. Sukarno then asked the architect R.M. Soedarsono to continue with the design. Soedarsono incorporated the numbers 17, 8 and 45, representing the 17 August 1945 Proclamation of Indonesian Independence, in the dimensions of the monument.
The construction of Monas proceeded in three stages. The 1st period, from 1961/1962–1964/1965 began with the official start of construction on 17 August 1961 with Sukarno ceremonially driving in the 1st concrete pile. A of total of 284 piles were used for the foundation block. A further 360 piles were driven in for the museum foundations, with work being completed in March 1962. The walls of the museum in the base were completed by October. Construction of the obelisk than commenced and was finished in August 1963. Work in the 2nd stage, from 1966 to 1968 was delayed by shortages of funding and the aftermath of the 30 September Movement coup attempt. In the final phase, from 1969–1976, the dioramas for the historical museum were added. Problems remained once construction was complete, and work was needed to solve problems with water leaking into the museum. Monas was officially opened to the public on 12 July 1975. The location of Monas is known as Merdeka Square.
The twering monument encapsulates the philosophy of Lingga and Yoni. Lingga resembles an alu rice pestle and Yoni resembles a lesung rice mortar, two important traditional Indonesian tools. Lingga and Yoni also symbolize eternal life with the lingga phallic symbol, representing masculinity, positive elements, and daytime and the Yoni the female organs symbol, representing femininity, negative elements, and night. The monument consists of a 117.7m obelisk on a 45m square platform at a height of 17m, the goblet yard. The obelisk itself is clad with Italian marble.
In the outer yard surrounding Monas there are reliefs of Indonesian history. The story begins in the northeastern corner and describes events during eras such as the Singhasari and Majapahit empires. The reliefs extend along the four walls showing the European colonialization of the Indonesian archipelago, various popular local uprisings, modern Indonesian organizations in the early 20th century, the Japanese occupation in World War II, the Proclamation of Independence, and post-independence developments. The reliefs were made from molded cement although several of the statues are damaged and have decayed due to weathering.
The Indonesian National History Museum has a display of dioramas in the large marble-lined hall below Monas. There are a total of 51 dioramas around the walls and in the centre of the hall. The dioramas begins in the northeastern corner, displaying the scenes from Indonesian history from the beginning during the earliest days of Prehistoric Indonesia, the construction of Borobudur, the Srivijaya and Majapahit eras, followed with events from the period of European colonization and uprisings against Dutch East Indies Company and Dutch East Indies rule. The dioramas continue well into the 20th century showing the Japanese occupation, the proclamation of Indonesian independence in 1945, the struggle for independence of Indonesian revolution, and on to events during the New Order era of Suharto's regime.
The Hall of Independence is situated inside the goblet or "cup" part of Monas (Indonesian: Cawan). The hall, which contains various symbols of independence, can be reached through spiral stairs at the north and south doors. The original text of the Proclamation of Independence is stored in a glass case inside the golden door on the west side of the inner wall. Mechanized bronze doors weigh 4 tons and are coated with gold adorned with the image of a Wijaya Kusuma flower, symbolizing eternity, and a lotus flower, symbolizing purity. The doors, known as Gerbang Kemerdekaan or the Gate of Independence, open slowly while the nationalist Padamu Negeri song plays followed by a recording of Sukarno reading the text of the Proclamation. On the southern wall there is a large bronze gold-coated statue of the coat of arms of Indonesia weighing 3.5 tons. On the eastern side is the text of the proclamation in bronze lettering. Originally the eastern side displayed the most sacred Indonesian flag, Sang Saka Merah Putih, originally raised on 17 August 1945. However because it is fragile and in poor condition it is no longer displayed. The wall on the northern side displays a map of the Indonesian archipelago coated in gold.
There is a middle platform on top of the cawan which provides visitors with views from a height of 17 metres. This middle platform is accessible through the elevator on the way down from the main observation deck (the lift stops on the way down at the cawan to allow visitors to exit) or through stairs from below.
A lift on the southern side carries visitors to the viewing platform at a height of 115 metres above ground level. The capacity of the elevator is about 11 people. The top platform can accommodate about 50 people. There is also a staircase for use in emergencies. The total height of the monument is 132 metres. The distance from the viewing platform to the tip of the flame is 17 metres. The ticket to observation deck is Rp.7,500 .
The observation desk and other facilities are open daily from 08.00-15.00 daily . The entrance to Monas is located around 100 meters away to the northern side of the monument. Visitors enter by steps down to a tunnel which leads back towards the base of the Monas. There is a ticket office (Rp 5,000 for adults, early 2013) at the end of the tunnel. Tickets allow access to the National History Museum display of dioramas as well as several other parts of the area. Tickets for access to the observation desk cost another Rp 7,500 for adults (mid-2012) and may be purchased at a 2nd booth after passing through the hall showing the diorama display.
It is best to go early, preferably arriving before 08.00am, and proceed directly to the lift to the observation tower. The lift has a capacity of perhaps 160 people per hour so long queues build up quickly. The other parts of the monument, including the dioramas in the hall below the Monas, can be viewed later.