An aerial drone photo taken on June 4, 2024 shows people visiting Heilongjiang Taiyangdao National Wetland Park in Harbin, northeast China's Heilongjiang Province. (Xinhua/Wang Song)

An aerial drone photo taken on June 4, 2024 shows a view of Heilongjiang Taiyangdao National Wetland Park in Harbin, northeast China's Heilongjiang Province. (Xinhua/Wang Song)

An aerial drone photo taken on June 4, 2024 shows a view of Heilongjiang Taiyangdao National Wetland Park in Harbin, northeast China's Heilongjiang Province. (Xinhua/Wang Song)

An aerial drone photo taken on June 4, 2024 shows a view of Heilongjiang Taiyangdao National Wetland Park in Harbin, northeast China's Heilongjiang Province. (Xinhua/Wang Song)

An aerial drone photo taken on June 4, 2024 shows a view of Heilongjiang Taiyangdao National Wetland Park in Harbin, northeast China's Heilongjiang Province. (Xinhua/Wang Song)

An aerial drone photo taken on June 4, 2024 shows people visiting Heilongjiang Taiyangdao National Wetland Park in Harbin, northeast China's Heilongjiang Province. (Xinhua/Wang Song)

An aerial drone photo taken on June 4, 2024 shows a view of Heilongjiang Taiyangdao National Wetland Park in Harbin, northeast China's Heilongjiang Province. (Xinhua/Wang Song)

An aerial drone photo taken on June 4, 2024 shows a view of Heilongjiang Taiyangdao National Wetland Park in Harbin, northeast China's Heilongjiang Province. (Xinhua/Wang Song)

An aerial drone photo taken on June 4, 2024 shows a view of Heilongjiang Taiyangdao National Wetland Park in Harbin, northeast China's Heilongjiang Province. (Xinhua/Wang Song)

An aerial drone photo taken on June 4, 2024 shows a view of Heilongjiang Taiyangdao National Wetland Park in Harbin, northeast China's Heilongjiang Province. (Xinhua/Wang Song)

An aerial drone photo taken on June 4, 2024 shows a view of Heilongjiang Taiyangdao National Wetland Park and city view in Harbin, northeast China's Heilongjiang Province. (Xinhua/Wang Song)