I was surprised to see this at Barnes & Noble today: a Lego model of Sungnyemun, one of Seoul's gates and better known in Korea and abroad as Namdaemun until it burned down in 2008. The iconic structure is being rebuilt, and you can play along at home. This particular model in the Lego Architecture series was retired earlier in the year, though, is no longer available on the Lego website. It's also listed as a product for girls, so apparently it was off-limits to half the population who might be interested in building a South Korean landmark. However, they still have a couple at the Cranberry location selling for the suggested retail price of $34.99.
If you're interested in building Korean models, you'll find more variety on G-Market, one of South Korea's online shopping portals. Browsing plastic collectibles turns up dragon ships and other old boats, traditional houses, the Blue House, and a whole Royal Palace Series, for starters.
A Sungnyemun plastic model, and the 12-item Royal Palace Series, and the Blue House, available from G-Market. It's the English website, and many of these models are available for international shipping, but the pages are often in Korean.