Kushiro-shitsugen National Park

Listen first. Wind moves through the reeds with a dry, steady hiss, like distant surf. Underfoot, the wooden boardwalk gives slightly with each step. Below the planks, the ground is not really ground at all. It is water, moss and roots, layered over thousands of years. In front of you, a flat sea of grass runs to the horizon, broken only by dark clumps of alder trees and the silver glint of a winding river.

This is Kushiro-shitsugen, the Kushiro Marsh, on the eastern edge of Hokkaido. It is the largest wetland in Japan. In a country famous for steep mountains and crowded coastlines, this place feels almost foreign. There are no peaks here, no temples, no busy roads crossing the centre. The land is low and open, and the sky takes up most of the view. Many visitors say they forget they are in Japan at all.

The marsh has a deep past. Geologists explain that thousands of years ago, during a warmer period, the sea reached far inland and covered much of this basin. As the climate cooled and the water pulled back, a shallow lagoon was left behind. Rivers filled it slowly with silt. Plants grew, died and sank into the cold water, and they did not fully rot. Layer by layer, those remains built up as peat — the spongy, dark soil that holds this whole landscape together.

Winding through it all is the Kushiro River. Look for its long, lazy curves from any viewpoint. The river bends back on itself again and again, in loops so tight they almost meet. It moves slowly here, because the land is so flat. In some areas, people straightened parts of the river channel during the twentieth century. Later, conservation projects began to restore some of the old bends, to bring natural water flow back into the wetland.

Now for the bird that made this marsh famous. The red-crowned crane, called tancho in Japanese, stands well over a metre tall. It has white feathers, a black neck, and a small patch of bare red skin on the top of its head. In Japan, the crane is a symbol of long life and good fortune. It appears on folding screens, wedding kimonos and old coins. And it came very close to vanishing from this country forever.

Here is the first surprise. By the early twentieth century, hunting and the draining of wetlands had pushed the crane to the edge. Many people believed it was already extinct in Japan. Then, in 1924, a small group of cranes was found living in this marsh. Only a handful of birds had survived, hidden in the reeds. This wetland was their last refuge in the country.

The recovery took decades. During hard winters, local farmers and residents began to put out grain and fish for the hungry birds. That feeding grew into an organised effort, and the cranes slowly returned. Today the Hokkaido population numbers well over a thousand birds. In winter, many gather at feeding grounds in nearby villages. In spring and summer, they spread across the marsh to nest in pairs, and they are much harder to spot.

If you visit in late winter, you may see the famous crane dance. Pairs bow, leap into the air, flap their wide wings and throw back their heads to call. The call is loud and trumpeting, and it carries across the snow for a long way. The dance is part of courtship, but cranes sometimes dance at other times too, almost as if for the pleasure of it. It is one of the great wildlife scenes of East Asia.

The cranes are not alone. Ezo sika deer, a northern type of sika deer, often step out at the forest edge in the early morning. Red foxes hunt along the paths. In the river lives the Japanese huchen, called itou, a large salmon-like fish that has become rare across Japan. And here is the second surprise. The marsh shelters the Siberian salamander, a small amphibian that lives in only a few places in Japan. Scientists see it as a survivor from colder ages, when northern species spread further south.

This importance was recognised early. In 1980, the Kushiro Marsh became the first site in Japan listed under the Ramsar Convention — an international agreement to protect wetlands of global value. In 1987, the area was declared a national park. In 1993, the city of Kushiro hosted a major international Ramsar meeting. So this quiet grassland has played a real part in how the world talks about protecting wetlands.

The weather here has its own character. In summer, cool fog often rolls in from the Pacific Ocean, and Kushiro is well known for its grey, misty days. On those mornings the marsh can look almost like a watercolour painting. The alders become dark shapes, and the river fades into white. In autumn the reeds turn gold and copper. In winter, snow covers everything, and the cranes stand out against it like paper cut-outs.

There are several ways to take it in. On the western side, the Hosooka observation point gives a wide view over the river bends, and it is a popular place to watch the sunset. Boardwalk trails lead out across the wet ground, so you can walk without damaging the fragile moss. On the eastern side, quiet lakes such as Lake Toro offer a calmer mood, and in season a slow sightseeing train runs along the edge of the marsh. Many visitors also choose to paddle a canoe down the Kushiro River, at water level, with only the sound of the paddle.

Before you leave, stand still for a moment. Look at the line where the reeds meet the sky, and notice how little moves except the grass and the clouds. Listen for a bird call, or the tap of wind against the railing. This land took thousands of years to form, and it nearly lost its most famous resident. As you walk back along the boardwalk, keep your eyes on the far reeds. A tall white shape there might be a crane... still here, after everything.