Visited just recently (November 2016), no doubt - one of Korea wonders, folk village that is completely different from other Korean villages.
The best town to start a trip is located in Southern Korean province of Jeollanam-do, Suncheon. From there - bus stop near intercity bus terminal - there are 4 different buses (16, 61, 63, 68) daily to Naganeupseong Fortress Town. They are not very frequent but the first should be around 8.00 a.m. (next one should be around 10.00 a.m.) The whole trip from Suncheon downtown should not take more than 40-45 minutes.
Uniqueness of Nagan Fortress Town (as it is called for short) lies in its layout. The whole village is surrounded by completely preserved walls with gates, moats and watching towers. While walls are a little bit of Joseon style (similar to those in Namhansanseong or Hwaseong), the majority of village buildings is covered with straw (tchatched roofs). What's more it is a normal village with residents trying to live normally despite huge number of tourists.
It is easy to combine visit to Naganeupseong with Seonamsa Temple located 18 km away. In fact there is a direct bus (16) that goes from central Suncheon to Naganeupseong then to Seonamsa and returns to Suncheon.