Penghu Marine Geopark is one of the first Geoparks in Taiwan which was recognized as the World Heritage (in 2005) and joined in the Taiwan Geopark Networks (2011). Penghu Marine Geopark is famous for its basaltic landscape and abundant marine ecology, combined with artifacts of 4000 years of human activity. Magnificent volcanic landforms are found everywhere, such as hexagonal or pentagonal basaltic rock pillars and lava platforms. Unique cultural landscapes and economic activities nurtured by Penghu’s particular geology, geomorphology, significant marine ecology and historical geography, are characteristic and charming. These are the entire geological and geographical milieu that gives Penghu Marine Geopark special value and socio-economic meaning.
Penghu Islands are located in the Taiwan Strait with 90 isles in total and are made of basic basaltic rocks, as a result of gradually cooled down magma that erupted from the ground. The islands are mainly platform-based and the physical characteristics of basic basaltic magma are less viscous and with high mobility, making them different from other volcanic islands with towering hills or mounds. In addition, large numbers of columnar jointed basalt cliffs surround the border of Penghu islands in distinctive ways, attracting many visitors.
Penghu islands have the oldest volcanic geology of Taiwan as a result of the collision between the Indian plate and Eurasian continental plate, and the subduction of the Pacific plate after the late Mesozoic. The effect of the collision was sea-floor spreading and plate divergent. It was mainly due to these divergent activities that large amount of lava flow oozed out into the Penghu archipelago area.The cooling of the basaltic lava flow formed highly regular columnar joints. These now display various slopes and shapes as a result of tectonic activity. Together with weathering and erosion, these basaltic columns exhibit diversity in forms. With the combination of special geological features, marine ecology, and human activities nurtured by maritime history, the uniqueness and importance of Penghu Marine Geopark are beyond words.