In the early 16th century the ruling power in Venice decreed that the city's Jews be confined to a small islet, in the northern Cannaregio region of the city, now known as the Ghetto. This islet was cut off from the rest of the city by wide canals, the sluice gates of which were maintained by Christian guards. The name comes from the Italian word for an iron foundry "geto", because of the building that had formerly occupied the site, and the word has subsequently been applied to enclaves of Jews throughout the world. As the number of Jews in the Ghetto increased, the only way for them to expand was by building upwards, and consequently the first "skyscrapers" of the city were erected here. In the 17th century the number of Jews living on this tiny island had reached 5,000. When Napoleon occupied Venice, he released the Jews, but they were forced back into the Ghetto shortly after this when Austrians occupied the city. Although only five Jewish families still live in the Ghetto, it still retains a strongly Jewish feel, with kosher shops, a Jewish library and two synagogues. The shops even sell glass figures of Hasidic Jews and rabbis, and menorahs. The Ghetto is a depressing place to visit, illustrating the deplorable history of persecution that the city's Jewish families have endured and the cramped conditions they were forced to withstand, and for this reason it's well worth the walk.