It's traditional now that I post something about it today.
I think we should take a brief look at the fort of Arad, where the martyrs were held captive and then executed.
Arad had a castle already in the 11th century as a center of the county. However it was some distance away, just as subsequent fortifications were erected all about. The current fort was ordered to built by Maria Theresia at cca. 1750. The spot was excellent since from three sides the Maros river surrounds it. The plan was drawn by general Philipp Ferdinand Harsch. It's a hexagon star fort, with ramparts, casemates, bastions, tenailles, lunettes and all that jazz. The tranches were able to be flooded by the river if necessary.
Just as Temes little further south (see pic #4), it was an important place so imperials held it from the start of the revolution, it had to be liberated from them, the defenders were granted free withdrawal and left on 1848 June 28.
After the surrender on 1849 August 17 general Damjanich - one of the martyrs - trusted the fort to the Russians (whom passed it on the the imperials).
After the War of Independence it was used as a prison. I think about 500 officers were held captive there.

In 1919 June, Romanian army took it over, then in 1944 September the Hungarian army entered and kept it for couple of days. Until 1958 Soviet troops were stationed there, even recently parts of it serves as barracks for the Romanian army, not sure what is the situation at the moment.