1133 Naengjeong-ri, Gwanin-myeon, Pocheon-si, Gyeonggi-doShow Map
Locally, Daegyocheon was developed along Western outskirts of Cheorwon Plain and meets with Hantan River mainstream near Goseokjeong Pavilion across the plain from east to west in the southern part of Cheorwon Plain. This Daegyocheon is characterized by bilateral cliff composed of basalt and basalt cliff of about 25m in thickness is exposed across about 1.5km. For this reason, Daegyocheon basalt gorge was designated as a natural monument in 2004, achieving recognition for scarcity and academic value as representative basalt gorge zone in Hantan River.p>
Stratigraphically, basalt of Quaternary fills the ancient stream channel formed by the erosion of Mesozoic granite. Rising hills around Cheorwon Plain are Mesozoic granite and Cheorwon Plain was made by lava erupted during Cenozoic Quaternary. Geological structures observed in Daegyocheon include columnar joint, plaste joint, fan-shaped radial joint and its feature is that the lava unit of three pieces is observed.