A quarter of Rotterdam’s residents are Muslim.

Evidence

Rotterdam is Europe’s busiest port and Holland’s second largest city, with a population of nearly 600,000, at least 25% of which is Muslim. Formerly said to have been home to Europe’s largest mosque (Mannheim now makes that claim) and likely future host to Europe’s first accredited Islamic University, Rotterdam has been the site of acute political tension between Muslim immigrants and the native Dutch. — Michael A. Reynolds and Thomas D. Grant, The Future of Europe and Its Muslims, 52

Categorization

• SHARE: A very specific urban-demography datum for someone tracking European port cities or Dutch politics.