South Korea is a highly developed country, ranking as the third-highest country on the Human Development Index in Asia. Its economy ranks as the world's tenth-largest by nominal GDP. Its citizens enjoy one of the world's fastest internet connection speeds and the most dense high-speed railway network. The country is the world's fifth-largest exporter and eighth-largest importer. Though South Korea shares one of the world’s most heavily militarised borders with North Korea, it is equally known for its green, hilly countryside dotted with cherry trees and centuries-old Buddhist temples, plus its coastal fishing villages, subtropical islands, and high-tech cities such as Seoul, the capital of South Korea, Jeju Island, and Busan.