When Seoul's Mayor, Mr Park Won-soon, proposed turning a disused highway into a pedestrian-only walkway in 2014, he was fiercely opposed by residents concerned about traffic congestion and shopkeepers worried that their businesses would suffer.
City officials hosted hundreds of town-hall meetings, and Mr Park spent days at the site listening to suggestions before the people finally came on board.
The sky park - named Seoullo 7017, meaning Seoul Road - has attracted more than 10 million visitors since it opened in May last year.
Elected to a third consecutive term last month, Mr Park is Seoul's longest-serving mayor and has helmed the transformation of South Korea's highly-urbanised capital, which won the Lee Kuan Yew World City Prize this year.
Mr Park, who will receive the prize at the World Cities Summit today, told The Straits Times in an interview yesterday that his background as a civic activist influenced his philosophy of giving citizens a say in how their city is run.
The former human rights lawyer founded the non-profit watchdog People's Solidarity for Participatory Democracy in 1994, and would collect people's views on issues and convey them to the government.
As mayor, he helmed the 2030 Seoul Master Plan, which city officials came up with over three years by listening to the opinions of thousands of citizens and experts.
"The top-down approach to decision-making almost always leads to failure or a lot of trial and error. The bottom-up way is much more effective because it listens to opinions of residents to reduce the number of trials and errors," he said.
"We are truly a listening city government. The citizens can tell us whatever they think, whatever opinions they have, because we guarantee them channels of communication and interaction."
Mr Park also receives feedback from his 2.5 million followers on Facebook, Twitter and Instagram, and will reply to them himself.
"At times, the comments and replies are very critical and I sometimes feel hurt. But as mayor... I should be able to know what is happening and understand their thoughts," he said.
Mr Park also spearheads a drive to make Seoul more pedestrian-friendly and to discourage people from owning and using cars.
"We want to pursue a 'Road Diet'," he said, adding that the city is reducing the width of roads to reduce the speed of cars while making bus rides smoother and faster.
"Citizens are very much accustomed, sometimes addicted, to cars, and when we decided to reduce car lanes... at first there was a lot of complaints and opposition."
But attitudes are changing and many young people now use the city's 20,000 public bicycles frequently, and have said they are very satisfied, he added.
Mr Park, who was first elected as an independent in 2011 but joined the Democratic Party headed by President Moon Jae-in in 2012, will not seek re-election as mayors can only hold office for three terms.
Asked about the legacy he wants to leave behind, he said: "I want to change the lives of citizens for the better. I hope they can remember me as the mayor who changed their lives for the better."
He also hopes for more exchanges between Pyongyang and Seoul during the rest of his four-year term. He suggested that both cities could host sports matches or have a joint orchestra.
Public servants could later build on these exchanges and expand into the areas of urban infrastructure, public housing, waterworks and sewerage systems, he added.
"If we can build up these exchanges I believe that the relationship between Pyongyang and Seoul can be a win-win relationship."