The interior of the Citadel is closed indefinitely. It is only possible to access the Statue of Liberty outside the walls.
Built as a military fortress on the highest point of Budapest's city centre by the Habsburg Empire in 1854, the Citadel allows for beautiful views of the city. From its walls, you can see all the major sights, including the Parliament, the Buda Castle or the bridges over the Danube river.
The majestic fortress was built from the blood and sweat of Hungarian prisoners, who were forced to work on its construction, following the suppression of the Hungarian Revolution of 1848. It only lasted in its full power for about 50 years though. When the fights for freedom were over and agreements were reached, the fortress still roused so much anger, that by 1900 its main gate had to be destroyed, along with its outer walls.
The interior of the Citadel is closed indefinitely. It is only possible to access the Statue of Liberty outside the walls.
Wikipedia https://en.wikipedia.org/wiki/Citadella
Address Citadella sétány, 1083 Budapest, Hungary
Coordinates 47°29'13.127" N 19°2'46.926" E