If you're in the mood for a manageable day hike with some incredible views of Seoul, consider the 3-hour round-trip climb up Mt. Yongmasan. At 348 m, this massif doesn't require much more than moderate fitness and a pair of hiking shoes, so it's a popular choice for locals and visitors in search of a scenic workout. And yes, as expected, you'll find that the trail (a mix of stone and stairs) is clean and meticulously well maintained. Thank you, South Korea.
Unexpected highlights of the hike include the Yongma Waterfall Park (we know how much you love 51-meter man-made cascades), a mid-hike fitness equipment setup and a makeshift bar at the summit, perfect for mixing alcohol and exercise. All kidding aside, however, the views of the South Korean capital are nothing if not spectacular from various lookout points along the way, and the hike can easily be (and usually is) paired with a visit to neighboring Mt. Achasan as well. Just set your sights for Exit 2 on Subway Line 7 and enjoy a day of trekking and picture-taking in the Land of the Morning Calm.