Beneath the Buda Castle District lies approximately 10 kilometers of inter-connected caves, cellars and cavers. Consisting of over 100 individual caves, It was used both in WW II and in the Revolution in 1956. It is truly an amassing experience to see how people, doctors and soldiers lived , healed and worked in such a place. Originally a storage area, then a hospital, then pharmaceutical work and finally a nuclear bunker. Totally unique.