The major islands that make up Japan are Honshu, Hokkaido, Kyushu, and Shikoku. Honshu is the largest and houses major cities like Tokyo and Osaka. Each island has its unique geography, culture, and climate, contributing to Japan's overall diversity. The country's location in the Pacific Ring of Fire makes it prone to earthquakes and volcanic activity, enhancing its fascinating landscape that includes mountains, forests, and coastal regions.