Kanmon Straits is a narrow channel of water that separates Honshu and Kyushu, two of Japan's main islands, while connecting the Sea of Japan with the Inland Sea. The strait has long played an important role in Japanese maritime history; the Shimonoseki Campaign — a series of military engagements with the U.S. and other navies that took place here in the 1860s — ended Japanese feudal rule over the region, thus opening Japan to the West and transforming it into an international trading hub. Twin 19th-centry lighthouses mark the port cities that face each other across the channel: Moji, Kyushu and Shimoneseki on Honshu, where you can still see cannons used during the naval campaign. Some 700 ships pass through Kanmon Straits on a daily basis; underground tunnels allow both cars and pedestrians to walk between the two ports. Japan’s largest fireworks display takes place over the strait every August, drawing more than a million sky gazers to watch the spectacular.