Sanmenxia City, west to Shaanxi Province, locates the south bank of Huanghe River, neighboring with Shanxi Province. The zigzagging Huanghe River, surging forth and traversing the mountains and passes, rushes down to hukou waterfalls ( between Shaanxi Province and Shanxi Province). With several Z-turnings, Hunaghe river is suddenly disconnected by Sanmenxia Dam ( the 1^st top Dam on Huanghe river ) and becomes exceptionally mild, which forms a marsh wetland with a coverage of tens of thousands of hectares in Sanmenxia city.

In each winter, migrant birds multiply. Since 2007, the number has reached over 100,000, including ten thousands of swans which attracts photographic lovers from 13 provinces ( Beijing, Sichuan, Hunan, Guangdong and Jiangxi Province ). More than 100,000 visitors como to  the Wetlands Park.

There are no explicited records of the date when swans firstly encountered Sanmenxia city. In 1960s, Sanmenxia city served as a transit stop where the migrated swans replenished the food and had a short rest. Then, the swans continued their southbound journey. With global warming worsening, swans had been residing here. The number has increased from dozens or hundreds in 1990s to ten-thousands so far. Therefore, it has got a poetic name --- Swan City.

Henan Huanghe River wetland national nature reserve takes 301 klilometers from east to west, stretching over Sanmenxia city, Luoyang city, Jiyuan city and Jiaozuo city, of which 205 kilometers are in Sanmenxia city. Swans in Sanmnexia city account for 95% of the total number in Henan province.

Swans mostly dwell in Wangguan village, Third Water Company and Shangcun village hubin county Sanmenxia city.  Besides swans, over 867 species of the first-grade state protection birds like black stork, white stork, bustard inhibite in the wetland. “Best place, best winter, Sanmenxia and swans are waiting for you.” has been used as the most powerful slogan of Sanmenxia city. Along with hundreds miles of beautiful Huanghe bank, thousands of swans like snow-lotus are dancing on the rippling clear river and the wetland full of green plants. The beautiful white angles sometimes sing cheerfully, sometimes whisper tenderly, sometimes fly high up in the sky, sometimes dance trippingly.  ( Translated by Zhengguofu )