If you start at the recommended starting point, Hwaseong Haenggung, the palace complex, there is a steep climb up to the walls. Halfway up you come to the road that circles the old city, below the city walls. There is no signpost telling you the way to go, and many first-time visitors will turn left and start walking down the road, as this is what most of the locals do. It is a popular route for walkers and joggers. But, this is NOT the fortress wall walking route. You need to clamber up the hill further until you get to the top and then turn right, walking inside the wall.
The route is marked with flags, which are a different colour in each section. On the first section, they are red. So, to avoid getting lost, always follow the line of flags.
In winter much of the route is dotted with muddy pools and patches of ice. So, you need good walking shoes. Everyday street shoes, with leather or plastic soles, will cause you numerous problems. Also, be prepared to get both your shoes and your jeans splattered with mud. In summer you will need to carry a bottle of water with you, as you will sweat a lot.
At Hwaseong Haenggung (the palace) there is a warning telling you that this is the last toilet before you embark on your 6km+, 3 hour circuit of Hwaseong Fortress. Think about it. There are no shady spots once you get up onto the fortress walls. People can see you from miles away.
One consolation is that this is one of the most special public toilets in the world. It is the only one I have ever encountered where you have "a room with a view", music plays, there are bunches of flowers above the urinals and half the people in the Men's section are women. There was almost a party atmosphere in there!
See accompanying photos.
One of the biggest problems of going around Korea is the language problem. People hardly speak or write English, and this is even worse outside Seoul in a city like Suwon. Even the information boards and signages are in Korean with no English translation.