Taehwa River National Garden is the largest urban water-friendly space in the country with water, bamboo, green barley, rapeseed, and greenery in a size of 531,000m2, 2.3 times that of Yeouido Park in Seoul. For the purpose of preventing floods, the Simni Bamboo Forest, which was once in danger of disappearing, was conserved by citizens. The 186,000m2 of land, which was decided as a residential area and planned for development in the urban planning, was returned to a river section to create today's Taehwa River National Garden. The Taehwa River National Garden was developed as an eco-friendly ecological park in which nature and humans coexist, including streamlets, bamboo park, outdoor performance halls, and embankment walkways, with a total project cost of KRW 119.6 billion from 2004 to May 2010. The main attractions are the Dragon swallowtail Ecological Garden, Bamboo Ecological Garden, Osan Pond, Saw-leaf Zelkova Road, Manhaejeong Pavilion, Outdoor Performance Hall, Bamboo Trails, Rape Flower Complex, and Green Barley Complex.