Olympic Park, Seoul

Listen first. Somewhere close, a cyclist rings a bell. Further off, there is the soft thud of a ball against a court, and the hiss of wind moving through tall grass. Under your feet the path is wide and smooth, built for crowds. But the green slopes rising around you are older than any path. Some of these hills were shaped by human hands long before Seoul was Seoul.

You are standing in Olympic Park, in the Songpa district in the southeast of the city. The park was created for the 1988 Summer Olympics, the Games that introduced modern South Korea to a global television audience. Several of the original competition venues still stand here. Around them, the planners laid out lawns, ponds, sculpture and forest. The result is part sports campus, part open-air museum, and part neighbourhood backyard.

Here is the first surprise. Long before the Olympics, this ground held a fortress. It is called Mongchon Toseong, which means the Mongchon Earthen Fortification. Historians link it to Baekje, one of the Three Kingdoms of ancient Korea, during the period when Baekje ruled from the Han River area. Those long grassy ridges are not decoration. They are the remains of earthen walls, packed layer by layer, roughly 1,700 years ago.

The fortress builders did not use stone for the main walls. They used soil, pounded hard in thin layers, a technique that can last a very long time when it is cared for. They also used the shape of the land, following the natural hills. Wooden palisades likely stood along the top, and a moat once added another barrier. Today the moat is a calm stretch of water, with ducks, reeds, and the reflections of apartment towers beyond the trees.

The fortress was studied seriously when the park was planned in the 1980s. Excavations turned up pottery, building traces and other everyday objects from the Baekje era. So the Olympic project did two things at once. It built for the future, and it uncovered the past. If you want to see what was found, the Hanseong Baekje Museum stands within the park grounds and tells the story of this early kingdom.

Now look for the largest structure near the main entrance — the World Peace Gate. It was built for the 1988 Games and designed by the Korean architect Kim Chung-up. The gate has two huge wing-like concrete roofs that spread outward from a central space. The shape suggests a bird lifting off, or a traditional roof with its eaves turned upward. Walk underneath and look up. The underside of the roof carries bright painting in a traditional Korean colour palette.

The area in front of the gate is a wide open plaza. On weekends it fills with families, skateboarders, children chasing bubbles, and couples on rented bicycles. This is one of the easiest places to feel how Seoul uses public space. People do not just pass through. They bring picnic mats, small tents and snacks from the convenience store, and they stay for the afternoon.

The second surprise is all around you, though many visitors walk past it. Olympic Park is also a large sculpture park. Artists from many countries contributed works around the time of the Games, and you will find pieces scattered across lawns, beside paths and on hilltops. Some are abstract steel forms. Some are playful. One of the best known is a giant bronze thumb by the French sculptor César, raised like a signal of approval. Keep your eyes open as you walk.

Then there is the tree. On one of the fortress slopes stands a single tree on an open grassy hill. Locals often call it the Lone Tree. There is no famous legend attached to it, as far as records show. It is simply a beautiful composition — one tree, one curve of land, and a wide sky. It has become one of the most photographed spots in the park, especially in soft evening light and after fresh snow.

As you move further in, the sports venues appear. The large domed arena, now known as the KSPO Dome, first hosted gymnastics during the Olympics. Today it is better known as a concert venue, and K-pop fans gather outside on show nights. Other halls held fencing, weightlifting, tennis and cycling events. Many still host sports, music and exhibitions, so the park stays active rather than becoming a frozen monument.

The seasons change this place completely. In spring, cherry blossoms and fresh green lawns bring out walkers in large numbers. In early summer, rose beds near the park's gardens add colour and scent. Autumn turns the trees gold and red, and fields of tall grasses move like water in the wind. In winter, the earthen walls become clear white lines under snow, and you can read the old fortress shape more easily than in any other season.

The park is large, so pace yourself. Paths connect everything, but distances between the gate, the fortress, the museum and the venues add up. Many visitors rent a bicycle or ride the small road train that circles the grounds. Others simply choose one area and walk slowly. There is no wrong way to do it. The park works best when you let it be a place to rest as well as a place to learn.

Before you leave, stand still for a moment on one of the earthen ridges. Behind you is a wall raised by people of an ancient kingdom. In front of you, the towers of a modern city rise into the haze. Between them, a child kicks a ball and a grandmother walks her dog. Feel the soft, firm soil under your shoes... and take that quiet with you as you walk back into Seoul.