I have been looking at what South Korea is like recently in anticipation of my brother heading off there for a year and this is a fascinating country. Not only are 21% of all people called Kim, but it is full of beautiful landscape, loads of culture, some amazing architecture and an incredible appetite for technology (which sounds right up my street).
I am definitely jealous of the fun he is going to have and with it being so close to Japan it is an excellent hub for discovering the rest of Asia. Cheaper than Japan too!
The one thing that I find really interesting is the food and especially some of the more exotic dishes. This national stew certainly sounds like something that you have to try, as long as you have the stomach for it.
On a more serious note there are some great pictures of Korea on this site: http://www.lonelyplanet.com/south-korea/images/steel-stairways-south-korea$4382-41