Po Pin Chau () is an island in

Hong Kong Hong Kong)., Legally Hong Kong, China in international treaties and organizations. is a special administrative region of China. With 7.5 million residents in a territory, Hong Kong is the fourth most densely populated region in the wor ...

. Off the eastern coast of the East Dam of the

High Island Reservoir The High Island Reservoir, located in the far south eastern part of the Sai Kung Peninsula, was opened in 1978, helping to alleviate water shortage problems in Hong Kong. Its water capacity is approximately 273 million cubic metres. The are ...

, the island is known for its hexagonal columnar jointing. The island was originally a

cape A cape is a clothing accessory or a sleeveless outer garment of any length that hangs loosely and connects either at the neck or shoulders. They usually cover the back, shoulders, and arms. They come in a variety of styles and have been used th ...

connected to the mainland, but eventually broke away from the mainland due to years of

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

. The island is administered by the

Sai Kung District Sai Kung District is one of the districts of Hong Kong, 18 districts of Hong Kong. The district comprises the southern half of the Sai Kung Peninsula, the Clear Water Bay Peninsula in the New Territories and a strip of land to the east of Ko ...

Geology

The columnar rock formations on the island were formed after a series of volcanic eruptions in Hong Kong during the

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...

period.

Conservation

Po Pin Chau is part of the Hong Kong Geopark and

Sai Kung East Country Park Sai Kung East Country Park () is a country park on the Sai Kung Peninsula in Hong Kong, measuring . It opened in 1978 and has features including: * High Island Reservoir * High Island * Pak Tam Au * Sheung Yiu * Wong Shek Pier * Beaches of T ...

. Po Pin Chau is part of the High Island Special Area (), which covers 3.9 hectares and was designated in 2011. The area includes the two islands Po Pin Chau and

Conic Island Conic Island or Fan Tsang Chau () is a small uninhabited island in Sai Kung District, Hong Kong. Its Chinese name derives from it being in the shape of " 甑" (), a crockery used in ancient times in steaming rice. There is a small lighthouse ...

and no part of High Island proper. The geology of the area is characterised by

volcanic rock Volcanic rocks (often shortened to volcanics in scientific contexts) are rocks formed from lava erupted from a volcano. Like all rock types, the concept of volcanic rock is artificial, and in nature volcanic rocks grade into hypabyssal and me ...

s of the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

period.

References

Sai Kung District Uninhabited islands of Hong Kong {{SaiKung-geo-stub