The part of Prague that saw the greatest transformation at the turn of the 18th and 19th century was the Jewish Quarters.
The Old Jewish ghetto in Prague, was established in 1215, after the issuing of the Lateran edicts by Pope Innocent III, this edicts severely affected the live of the Jewish population of Prague, by making it mandatory to segregate the Jewish population from the Christian majority, through the creation of a walled ghetto. I also forbade Jews from living anywhere else other than the Jewish ghetto, forbade Jews from owning the houses they lived in, and the land the houses were built on. Also,the Jews did not incest in the infrastructure of the ghetto, because they never knew when the would be chased out in an antisemitic pogrom.
Therefore, by the late 1800s the ghetto was in a state of squalor and dilapidation because it had sewage systems, paved road etc, it had the attributes of a slum.
Further more, by the mid 1800s, the Jews in Prague were allowed to own Real Estate property, and because of the affluent status, most Jews could afford to vacate the dilapidated ghetto and move the the upmarket suburbs on Prague.
This left, the ghetto depopulated of its originally Jewish inhabitants and allowed for the lower classes of society to move in.
That is why, in the later part of the 1800s the derelict ghetto had a reputation of a red light district, complete with a number of brothels.
After a lenghty debate , it was decided that the necessary infrastructure could not be fitted in and that meant that the old ghetto, with it picturesque cottage houses would be demolished.
While most of the residential houses were demolished most of the original synagogues remained untouched and today they form the basis of the Jewish museum in Prague.
After the demolition was completed, the street level in parts of the ghetto were raised by about 2 meters to combat the ever present risk of flooding.
The newly cleared lad then served as the foundation of the Jewish ghetto as we know it today , which is dominated by revivalist architecture and the then fashionable Art-Novae architecture.