Cheonseongsan

Cheonseongsan rises 920.17m along the border between Yangsan and Busan's Gijang-gun. Its best-known route follows Naewonsa Valley uphill, earning it a spot on the official "12 Scenic Views of Yangsan" list.

Beyond hiking, the mountain is remembered as the stage for a landmark moment in Korean environmental activism. When the Seoul-Busan KTX high-speed rail line was routed through a tunnel beneath the mountain, the Buddhist monk Jiyul led hunger strikes and prostration protests demanding construction stop, citing damage to wetland habitat for the Korean clawed salamander — a case so unusual that the salamander itself was named a co-plaintiff in the resulting lawsuit. The original environmental review had missed dozens of protected species later confirmed by field surveys.

Today the controversy has faded, leaving a quiet trail along the valley for hikers.