If you've been to the Citadel in Hue, Vietnam then this place seems to be its counterpart. The ancient city was protected by a wall and entrances/exits are through massive and elaborate gates. At the center of it all lies the royal palace or Forbidden City, and the one here in Suwon is the Hwaseong Haenggung which sits at the foot of a hill. Like the palaces in Seoul, this palace is but a reconstruction of the original which was destroyed decades ago. There's not much to see inside them as the halls and rooms are all empty, so I'd give this place a miss if you've been to any of the palaces back in Seoul. As for the rest of place within the wall's confines, they're all modern buildings and streets so this was a bit of a let-down for me considering that this place is supposed to be a World Heritage site.
That leaves the main attraction which is the Wall. Just a little over 5 kms. long, it's hardly a contender against China's Great Wall. Its main appeal are the different designs of the watch towers along its length which one can view fast-track by riding the Hwaseong trolley.
This city is a suburb of Seoul, with close to a million people. Its main attraction is the Hwaseong Fortress built in the 1790s under King Jeongjo. This is a great place to walk, and take in the views of the city. It stretches on for over three miles, and is listed as a UN World Heritage Site.
Suwon's largest gate-- probably the main enetrance to the inside the fortress of Hwaseong -- is called Paldalmun. It's worth taking a look at but is also a good landmark to use when directing taxis from the train station. If you get off here, you can't miss the fortres or the palace.
In the late 18th century, King Jeonjo moved the burial site of his father to Mt. Hwason near Suwon. In order to have a place to stay while visiting the burial site, he constructed a small palace in the city. That palace (Hwaseong Haengung) has been restored and can now be visited for W1000. Compared to the palaces in Seoul, it is small and simple, but that's also what makes it interesting.
Like the palaces in Seoul, they also have a changing of the guard here. The difference is that the guards wear military battle dress in Suwon rather than the colorful court robes of Seoul. This adds a more martial flavor to the ceremony.
If you are looking for a pleasant day trip outside the heart of Seoul, Suwon would be a good choice. Still accessible by subway (Line 1) you can be there in an hour from City hall if you take the right train (Line 1 South has two endings and I got on the wrong train -- be careful!) Suwon is surrounded by a restored fortress wall known as Hwaseong, which is a UNESCO World Heritage site. When the weather is nice (a rarity in Seoul) this makes for a pleasant stroll. I went in the spring while the azaleas were in bloom, adding to the beauty. Started by King Jeonjo in the late 18th century, the walls were built to protect his palace in town. Since the fortress's construction was begun around the time of the first European contacts, new designs were incorporated, making it a marvel of the age (for Korea). If you walk around the entire circumference, expect to pass 2-3 hours -- all pleasant. If you don't have time to devote to the entire walk, make sure you go clockwise from Paldalmun -- you get a steep climb but the best views.
Traditional Korean bells are fascinating, large bronze constructs that are rung by driving a log against the shell. It is possible to see such bells many places in Korea, but the only place I got to ring one was in Suwon. As you walk the Hwaseong Fortess clockwise, you will come upon this bell on the right, not too far from Paldalmun. Take a chance to ring it, because, as far as I know, it will be your only chance.
I concur with everytbing that is written by mhj22. This really is worth a look. We stopped by on the way back from the Korean Folk Village (which we found a little disappointing). Although built in the 18th century, it really feels Medieal. Lots of locals make the most of this area and walk or run around the wall of the fortress. You get quite a few of the city.
Suwon is a large town about 1 hour south of Seoul. It has been designated as a world heritage site. The city has an old wall which is completely intact and takes about 2-3 hours to walk round. There are several fortifications at regular intervals with commanding views over the city and suronding mountains. There is also a an impressive palace complex.
The city is definetely worth a visit. It's surprising that this place is not widely publicized..... All the hotels in Seoul carry countless brochures for trips to the DMZ, but ths is far more interesting. The best way to get there is by bus which only cost 15,000 Won (US$1.5). Get off as soon as you go past the football stadium and through the first gate of the wall. It is also possible to reach Suwon by train from Seoul station but the train is slower and more expensive than the bus.
For restaurants head over towards the station side of town which is much more well develped.
A really nice spot for a morning coffee is the garden next to the bridge over the river. From the turret that commands that position there is a shop with lots of large kim-chi jars. This is a cafe with a very comfortable deck and views of the garden and wall beyond.
The best time to visit Suwon is during the fetival in the begining of October. The parade is fantastic with literally thousands of people in traditional costume. It's a very entertaining experience!
If you want to get out of Seoul and the DMZ does not appeal to you, then this place has go it all!
Suwon has an exellent web page in English at www.suwon.ne.kr