Yandang Mountains, Mountain range and geopark in Wenzhou, China

The Yandang Mountains are a coastal range in southeastern Zhejiang, divided by the Oujiang River into North and South Yandang. The core of North Yandang is a volcanic caldera about 13 square kilometres wide, built from ignimbrite, rhyolite, syenite and tuff laid down in four eruptions. Its layered cliffs and freestanding rock pillars, such as the two weathered spires at Lingfeng, rise above forested slopes.

The Yandang Mountains were formed by volcanic activity during the Cretaceous period, about 100–120 million years ago. The Yandangshan caldera, a round volcanic-intrusive complex 13 square kilometres across, erupted in four episodes; its north-east part was later destroyed by a regional fault. The layered ignimbrite, rhyolite, syenite and tuff create terrace-like structures. The area became a National Geological Park in 2004 and joined the Global Geoparks Network in 2005.

The name Yandang, "Wild Goose Pond," comes from a lake on the summit where wild geese were said to rest on their spring migration. Many temples stand inside caves or at cave mouths; the Guanyin Temple in the Lingfeng Peaks area, first built in 265, fills a 100-metre cave between the Holding Palms Peak with nine levels, its shrine at the highest, most hidden point. Most temples were destroyed during the Cultural Revolution and later rebuilt.

Different sections of the mountains have varying access conditions and hours, so checking ahead is helpful before your visit. Trails are generally marked, but sturdy footwear and plenty of water are essential for hiking in the mountainous terrain.

The Guanyin Temple in the Lingfeng Peaks area was first built in 265 and sits in a 100-metre-high crack-like cave between two leaning peaks known as Holding Palms Peak. Its nine levels follow the cave's steeply sloping floor, with the Guanyin shrine in the highest, most hidden section.