<P> Barcelona had a great citadel built in 1714 to intimidate the Catalans against repeating their mid-17th - and early - 18th - century rebellions against the Spanish central government . In the 19th century, when the political climate had liberalized enough to permit it, the people of Barcelona had the citadel torn down, and replaced it with the city's main central park, the Parc de la Ciutadella . A similar example is the Citadella in Budapest, Hungary . </P> <P> The attack on the Bastille in the French Revolution--though afterwards remembered mainly for the release of the handful of prisoners incarcerated there--was to considerable degree motivated by the structure being a Royal citadel in the midst of revolutionary Paris . </P> <P> Similarly, after Garibaldi's overthrow of Bourbon rule in Palermo, during the 1860 Unification of Italy, Palermo's Castellamare Citadel--symbol of the hated and oppressive former rule--was ceremoniously demolished . </P> <P> Following Belgium declaring independence in 1830, a Dutch garrison under General David Hendrik Chassé held out in Antwerp Citadel between 1830 and 1832, while the city itself had already become part of the independent Belgium . </P>

Describe the citadel area of the cities of indus valley civilization