Lodz was integral to the European cloth and textile industry, and by the early 20th century it was one of the most industrialized and most densely-populated cities in Poland. During World War II, Lodz was home to the second-largest Jewish ghetto in Europe, and today much of that old ghetto is the site of one of the continent's largest Jewish cemeteries, where over 180,000 people are interred. Urban renewal can be seen in the Manufaktura complex, where Lodz's largest public square is located and where former cotton factories are now venues and spaces promoting culture and the community. No trip to Lodz would be complete without a stroll down the three-mile length of Piotrkowska Street, one of the longest 'main streets' in the world, and a hub of nightlife.