Fes (Fez), Morocco

With a population of over 1.1 million, Fes is a dense, historic city with little room to grow. The old medina district, a UNESCO World Heritage site, remains a maze of narrow streets unsuitable for cars, complicating daily life. And while the Moroccan government has taken steps to preserve the city's heritage, the deterioration of buildings is an ongoing challenge. Bureaucracy, too, is a persistent headache, with the city's administrators struggling to balance preservation and development. Yet Fes also offers an unparalleled glimpse into Morocco's past, from its centuries-old mosques and madrasas to its bustling souks and tanneries. For those seeking an immersive cultural experience, Fes may be a rewarding - if at times frustrating - destination.