In Seoul's recent mayoral election, one campaign promise stood out. Rather than focusing on stabilizing housing prices, accelerating redevelopment, or transforming Seoul into a global tourist destination, the leading pledge was to make the city a "healthy city." Living healthily requires many conditions. A city where people can live healthily must have clean air, pure water, plenty of places to exercise across the area, and low levels of stress. When you think about it, a healthy city is essentially synonymous with a green city. Trees throughout the city help keep the air clean, while abundant greenery offers relief from the summer heat. Deep mountains and dense forests provide clean water. Parks scattered throughout the city and well-maintained walking trails make physical activity a natural part of daily life. The fragrance and scent of grass from a downtown garden, encountered by chance after a tiring workday, wash away the day's stress.

The statement that a green city is a healthy city is not merely a metaphor. When the United States declared war on obesity in the name of public health, an intriguing research finding emerged: the better children's access to parks, the lower their obesity rates. Studies also found that people living in neighborhoods closer to parks were less likely to suffer from chronic diseases. During the COVID-19 pandemic, studies also found that people living near parks experienced lower levels of depression. Another study showed that parks with walking tracks encouraged the elderly to be more physically active. Numerous domestic studies confirm that the more greenery there is and the more equitably it is distributed, the healthier urban life can be.

So why do people visit parks? According to one study, the activity Koreans engage in most often at parks is simply walking. And the park scenery people prefer most is lush, verdant landscapes reminiscent of forests and mountains. In other words, people visit parks primarily to walk while enjoying nature. What is striking is how obviously true this finding is. In a country where trends change at lightning speed and where everything seems to need to be stimulating to earn a "like" these days, people are choosing to walk in nature. When this preference for walking in green spaces aligns with research demonstrating that greenery significantly contributes to healthy living, we can begin to envision what a vibrant, healthy Seoul should look like.

That more greenery creates a healthier environment may seem like pure common sense. Yet in terms of public policy, the connection between greenery and health is more distant than one might expect. Health belongs to the fields of public health and medicine; leisure falls under sports and physical education; parks and green spaces are the province of landscape architecture. Therefore, health is handled by doctors, leisure by sports experts, and parks and green spaces by landscape architects. While everyone recognizes that these fields overlap, opportunities to collaborate in shaping the city have been rare. Yet a city where daily life is healthy?a city that is always full of vitality?becomes possible only when these three domains converge. Fortunately, that collaboration is not as difficult as it sounds, because citizens are already forging their own formulas for healthy urban living.

You open the "Wrist Doctor 9988" app and head out to a nearby park. After a light warm-up, you start jogging along the trail. Before you know it, you've reached the Han River. The futsal courts, tennis courts, and basketball courts along the Han River are packed with people working out. Having pushed yourself a little too hard today, you decide to ride a "Ttareungi" public bike on the way home. Along the way, you stop at the newly opened "Seoul Mulbit Naru" waterfront pavilion beside a neighborhood stream, enjoy an iced coffee, and take a short rest. As you get closer to home, you notice a garden center that has opened near the hillside behind the neighborhood. Children are holding trowels and listening to someone explain about flowers. Next weekend, you think, you should take the kids up the hill and then visit the garden center. Citizens are already weaving together these scattered opportunities to build their own version of a healthy city.

So what remains for policy to do? Unfortunately, the connected, ideal healthy-city scenario described above is not yet a reality available to everyone. Some people still have to ride a bus for quite some time just to reach a streamside trail with a "Mulbit Naru" pavilion, and many neighborhoods still lack parks large enough for exercise. Public gardens are being created throughout the city, and garden centers have been established to help people care for them, but these facilities still feel out of reach for many residents. Seoul Fitness Centers, which offer free physical fitness assessments, are being established, but they are difficult to find along the everyday walking routes and parks people actually use, and many residents do not even know they exist. The role of public policy is to connect these scattered resources into a network that everyone can access, and to provide underserved communities with the new resources and spaces needed to support healthy living. My hope is that green space will serve as the thread that ties together these various facilities and programs for a healthy city?as greenery is an indicator not only of the health of people of all ages and genders, but also of the well-being of plants, animals, and ultimately the environment as a whole.