How did the relative location Korean peninsula influence the development of Korean Civilization?

The geography of the Korea kept it isolated from other nations. A mountain chain seals it off from China. The Sea of Japan is a treacherous body of water that separates it from Japan. Korea has been called the "Hermit Kingdom". In spite of this however, Korea has been conquered by other nations; China, Japan, the Mongols. Buddhism and Confucianism entered Korea from China.