The Anyang Art Park 안양예술공원, located near Anyang station.
Photo credit : Hermann Maier Neustadt, Germany, aziz-m on flickr.
Built around a swimming pool that uses clean water sourced from the valleys of Gwanaksan and Samseongsan Mountains. The Park is fully equipped with a variety of recreational facilities such as an artificial waterfall; open-air stage; exhibition hall; square; walking path; and a lighting facility. With limpid waters flowing through the nearby valley and lush forested surroundings, the park is an easily accessible resting place near the Seoul metro area.
Photo credit : http://cafe409.daum.net
Take subway line 1 to Gwanak Station exit#2, catch bus 1, 51, 5624, 5625, 5626, 5530 or 5713, get off at the Anyang Art Park intersection and walk for five minutes or walk to the park approx in 10 minutes.
Reference : visitkorea.or.kr