UPDATE: The site has clearly changed into a general host for user-created maps, and now I can't see where those cool overlayed maps have gone, and don't care enough to find out again. So in the meantime you can waste time by glancing through some of these user-created maps:
- Halal Food Restaurants in Korea - Google Maps Gallery
- Casinos in South Korea - Google Maps Gallery
- Embassies in North Korea - Google Maps Gallery
- Rock Climbing - Korea - Google Maps Gallery
- Nuclear Facilities in South Korea - Google Maps Gallery
That last one is a little scary. Nobody show that to the governmental regulators or Google will never get their permission to make more detailed maps.
Here's that Halal Food map just for fun. Useful if you're a Muslim traveler to Korea and looking for Halal food.