Straddling the Han River in northwest Korea, Seoul traces its roots back millennia; it is now the world's 10th-largest city. The greater Seoul metropolitan area, which includes the major port city of Incheon as well as several satellite cities, has a population of nearly 23 million. Within this vast, teeming network, 12-lane highways wind among massive markets and royal palaces. The layers of Seoul's history as a center of power are ubiquitous: The old Joseon Dynasty city has become the modern-day downtown; Gyeongbokgung and Changdeokgung palaces are the two most prominent emblems of regal grandeur. The 21st-century attractions are as impressive as the remnants of antiquity. Thanks to the city's role as host of the 1988 Olympics, the subway system is extensive, efficient and foreigner-friendly. Sports complexes and massive shopping centers abound. Lotte World, a shopping center combined with an Olympic-sized skating rink and the world's largest indoor theme park, is a spectacle worth beholding. To escape the city fray, ascend nearby Mount Inwang, home to a Buddhist temple, a shamanist shrine and a commanding view of Seoul's staggering scale.