There is a partly natural and partly artificial maze of two and three-level cellars winding beneath the Buda Castle.
The upper level consists of 3-8-metre deep isolated cavities, whilst there are individual and a network of cellars in the lower level.
The Buda Castle cellar, deep cellar and cave system.
Hot springs gushed up from the Castle Hill about 350,000 years ago. As an outcome of their high calcium oxide content, they formed a layer of limestone covering the Buda marl shaping the base if the hill and the layer of alluvial deposited by Ördögárok stream. After a while, these surging hot springs were unable to penetrate the sediment they deposited, and consequently ran towards the area bordering the Buda marl and the fresh water limestone, where the hot water washed away the lower limestone layers and the looser layers beneath the limestone.
The multi-tier cellar system played numerous roles over the course of history. In medieval times, wine and crops were stored in the separate upper cellars, while the wells carved in the lower level ensured water supplies for the population up to the 15th century. Naturally, there are certain points in this underground network where there is a connection between the two or three levels, which is how it is possible to penetrate through to the core of Castle Hill through private cellars beneath houses, whilst the Labyrinth even makes it possible to emerge from this maze of tunnels through the exit of another building. By exploiting this characteristic of the cellar network, it was also used for military purposes during the era of Ottoman occupation. The cellars mostly used to store wine and supply water lost their significance after the vineyards of Buda began to disappear and the drinking-water network was built, which is why construction debris and rubbish was thrown into these cellars, which were consequently slowly forgotten; however, this maze of labyrinths remained alive as a legend.
Various geological scholars rediscovered the Castle Hill in the 19th century. József Szabó was the first outstanding scholar to document the geological composition of the Castle Hill, after which Tamás Szontagh was the first scientist to carry out detailed geological and hydrological research. The cellar-mapping work completed by Ignác Schubert made it possible to explore and repair the deep network of cellars in the 1930s and make it accessible to visitors. Kadič Ottokár and the Speleological Society carried out this work, as an outcome of which, the stretch of tunnels beneath Szentháromság street, known as the Castle Hill Cave was opened to the public in 1935.
The maze of cellars and cellars winding beneath the Buda Castle was soon also discovered by the army, after which bomb shelters and bunkers were created by carrying out major construction work. Even a small hospital was set up in these cellars concealed by Castle Hill during World War II. Civil defence organisations modernised these bunkers during the cold war. Entry was prohibited; private entrances were walled in and sealed off from the public.
In 1961, the Hungarian Speleological Society re-opened the extended and transformed tunnel running beneath Szentháromság street known as the Speleological Museum. The exhibition installed at this location was moved to Úri Street 9 in 1965, since the Budapest History Museum accommodating the exhibition was unable to continue to maintain and operate the stretch handed over in 1961. The exhibition mostly presenting historical artefacts accommodated in the tunnel beneath Úri Street was open to visitors right up to 1976, at which point the museum was closed due to financial and technical problems, as well as because water inundated the cellar system.
The 10,000 square metre Panopticum, otherwise known as the Buda Castle Labyrinth, where the various stages of Hungarian history are on exhibit, opened in 1983 along a 1,500-metre stretch of the network of cellars hence establishing the longest and best-structured stretch of the Buda Castle maze of tunnels open to visitors.
Thanks to reconstruction work that began in 1996, the vast part of the nearly 10,000 square-metre maze of cellars and cellars was returned to its original, pre-war state.
The panopticum illustrating historical events was replaced by symbolic and mystical exhibitions with a deeper meaning.
A történelmi eseményeket illusztráló panoptikum-kiállítást pedig szimbolikus, mélyebb érelmű, titokzatos kiállítások váltották fel.