Once you've reached the point where the non-stop shopping, eating and partying has worn you down, and all you want is some peace and quiet with a nice view, do what locals do . Start climbing to Namsan Park. It's one of those Seoul spots that is on the beaten track and can be over-run with both tourists and locals. But if you go at the right time and with the right attitude, it could become one of your favorite Seoul memories.
The best time to tackle Namsan is early mornings or around sunset. If you go in the middle of the day (or during cherry blossom season) be prepared to dodge selfie sticks and tourist hordes. For the ambitious types, an additional hike requiring a couple of hours of work provides a view well worth it. For those with limited time, there's also an option to take a cable car to the very top.
Panoramic views of Seoul's sprawling neighborhoods, particularly beautiful at sunset and after dark when the city lights are on full blast, await upon reaching the summit. If you are craving a different vantage point, you can pay a fee to enter N Seoul Tower, though the views aren't much better. However, for those who have a love of Korean dramas, the entry ticket grants you a visit to the “locks of love” (located on the Tower's terrace) where you can place yourself at the setting of many popular kdramas and korean couples in the throes of new love.
Even if you're alone, practice self-love and dedicate a love lock to yourself while watching the sunset… by yourself.