Józef Friedlein, mayor of Kraków in the early 20th century, had the custom of doing a circuit of the whole town of King Krak on foot. It was not a difficult task. The town, with a large population, hemmed in by the Austrian fortifications, occupied merely an area of 8 square kilometres, out of which over 1 square kilometre was occupied by the Błonia. This huge meadow in the middle of the town served as a field airport, as well as fodder reserve for cavalry, which enjoyed a rather high status in those days. He who wished to live outside the ramparts, had to pay customs duty for entering the town, and, he was also forced to sign so-called “demolition bond", which obliged him to demolish his buildings, at his own expense, at each demand of the army. Therefore very few people were keen on investing outside the present centre of the town. A hundred years earlier, at the beginning of the 18th century, Kraków was suffocating within its mediaeval city walls, overlaid with the present-day line of the Planty park, and, although it was inhabited by about 8,000, there was still plenty of free space. Over 40% of its area belonged to monatsteries, located nearly in every street. Just before the Second World War, plans for "Great Kraków" were made, which, however, could be implemented only in the 1920s, after Poland regained independence. The erection of the Nowa Huta Steelworks after World War II, and the development of the peripheral housing projects, has changed a the “Small Kraków" (Krakówek) of the beginning of the century into one of the greatest metropolises in the country.