A Dragonfly - Jamjari (잠자리) in Korean, settled on a wall outside the Seoul Museum of History (서울역사박물관). They are a common sight in Korea, and ones in the cities and popular tourist areas tend to be quite tame.
From Wikipedia ( http://en.wikipedia.org/wiki/Dragonfly ):
A dragonfly is a type of insect belonging to the order Odonata, the suborder Epiprocta or, in the strict sense, the infraorder Anisoptera. It is characterized by large multifaceted eyes, two pairs of strong transparent wings, and an elongated body. Dragonflies are similar to damselflies, but the adults can be differentiated by the fact that the wings of most dragonflies are held away from, and perpendicular to, the body when at rest. Even though dragonflies possess 6 legs like any other insect, they are not capable of walking.
Dragonflies are valuable predators that eat mosquitoes, and other small insects like flies, bees, ants, and butterflies. They are usually found around lakes, ponds, streams and wetlands because their larvae, known as "nymphs", are aquatic.
Bottom of image cropped off in Capture NX 2