Osaka, Japan’s second-largest city after Tokyo, has historically been the country's leading commercial center, with early trading connections to Korea and China, and it remains a major container port. Because of its importance, the city was flattened during World War II, although visitors today won’t find a hint of that destruction. Laced with highways, some elevated, as well as a network of canals, modern Osaka is famous for having hundreds of bridges. It's also home to one of Japan's landmark castles, and has a much-celebrated nightlife scene.