The fortress was a defensive complex subject to constant modification. The nearer in time the outbreak of World War I was, the more intense the development of technology and the more furious the arms race became. In order to retain their defensive capacity, individual battlements of the fortress had to be as little visible to outsiders as possible and to blend with the landscape while having control over the area to be defended.
Even today we can see the structures of the fort in various parts of the city, when they partly protrude from the ground or form a part of land elevations or slopes, majestically rising above or falling below the ground level. Sometimes only remnants of them are visible, made noticeable by irregularities in the surface of the ground, now grown over with trees and shrubs.
Fortifications were not only intended to be invisible to the enemy, but also capable of conducting active defence through artillery fire in various directions, so they were often located on hills in order to have a wide field of fire and thus control over the surroundings.
For the purpose of reconciling those frequently contradictory aspects of concealment and observation and trying to win the arms race, forts with their gun emplacements, gun crews and munitions magazines were sunk halfway into the ground and made to blend in with the environment. Planted over with masking greenery, they occupied the hills and guarded access ways to the Fortress. After the takeover of forts by the Polish Army, which handed over surplus facilities to civil institutions after many decades, the preponderance of this former fortress site has been retained as an undeveloped area.
Instead of being turned into housing tracts, the hills are still enclaves of greenery surrounding the centre that offer space for people to relax and have fun, but they also serve as a refuge for animals. Tourists and inhabitants visiting Kraków can still admire the panorama of the city and its surroundings from many points towering over the city. Had it not been for reasons of military security, the hills around Kraków would have probably become a place of suburban housing development and access to many observation points would be in doubt due to trespass laws.
Other currently unique lands stretching out in broad and level expanse across a few dozen hectares have also survived thanks to the Kraków Fortress. The most widely known area is Błonia Park – the internationally unique Great Meadow in the centre of the city, which has been untouched by development so far. In the days of the Kraków Fortress, it was used for training, drills, and parades by garrison troops; today, it delights townspeople with the opportunity to take walks or relax on the grass or with free space for the organisation of sports or cultural events. Another area worth mentioning is Błonia Rakowickie, on which the command of the Fortress established an airport in Rakowice in 1912; later it was expanded towards Czyżyny in the period of the Second Polish Republic and Nazi occupation and closed to air traffic in the 1960s. The airport and its surroundings had been partly built up until then, but they still contain free space of a few dozen hectares that allows inhabitants and tourists to walk in the open area among the greenery, and it is planted with hedges and trees on its circumference.