Seriously, these photos were just taken with my phone. Imagine how great it would look if you had a camera where you could really control the light and all of the other settings!
I took my parents earlier this week and we were pretty lucky. It was a pretty clear day, which was great considering how bad the air quality has been these days!
One bad thing that has changed since last year when I discovered it...there is some construction going on, so there is a lot of ugly blue tarp in the foreground if you do a panorama (see below).
The secret location is...
The rooftop garden on floor 8 of the National Museum of Contemporary Korean History.
Location: Gwanghwamun Station (line 5), exit 2
Walk straight past the US Embassy and the museum will be the very next building.
(You can learn about Korean history, too, if that's something you fancy.)