Hwaseong is one of the best preserved fortifications in Korea, despite suffering severe damage during the Korean War. There are countless fortresses in Korea, some spectacular, but if you only have time for a few, make sure to visit Hwaseong and Namhansanseong. I walked the entire wall, it's a pleasant couple of hours, with interesting stops along the way, and a fair bit of exercise. Additionally, there is an archery area that provides a great activity amongst friends. Regarding accessibility, the fortress is also conveniently only a long subway ride from Seoul.
One might wonder why such a prominent fortress is located in Suwon? Hwaseong Fortress is a product of the Reign of Jeongjo of Joseon (1776-1800). Jeongjo is a widely celebrated monarch in Korea, he sought to relocate the capital from Seoul to a new location: Hwaseong (a name chosen by Jeongjo himself). The fortress that many of us have visited is only one legacy from King Jeongjo's ambitious plan as many surrounding historic sites compliment the fortress, including the inscribed Joseon Yungneung Cluster.