The National Monument (Indonesian: Monumen Nasional, abbreviated Monas) is a 132 m (433 ft) tower in the centre of Merdeka Square, Jakarta Pusat, symbolizing the fight for Indonesia. These Obelisk monument, built to commemorate the struggle for Indonesian independence.
Construction began in 1961 under the direction of President Soekarno. 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 until 16.00 Western Indonesia Time (UTC+7) throughout the week except for the Mondays when the monument is closed.
Since April 2016, the monument also opens during night time, from 19.00 until 22.00 in Tuesday to Friday, and from 19.00 until 00.00 in Saturday and Sunday.
Source : Wikipedia