Coast · Hong Kong
Hong Kong UNESCO Global Geopark
香港联合国教科文组织世界地质公园
Hexagonal volcanic columns and red sedimentary islands in Hong Kong's eastern waters
The Hong Kong UNESCO Global Geopark covers the coasts and islands of Sai Kung and the north-eastern New Territories, where hexagonal columns of volcanic rock from a supervolcano of about 140 million years ago stand beside sedimentary islands of red, layered rock. Established as a national geopark in 2009, it joined the Global Geoparks Network in 2011.
- UNESCO Global Geopark · 2011
- National geopark · 2009
- Country parks and marine parks (within the geopark)
Key facts
Overview
Only a short distance from one of the world's densest cities, the geopark protects a coastline of cliffs, sea caves, arches, stacks and islands. It is divided into two regions. The Sai Kung Volcanic Rock Region, in the east, is known for its columns of fine-grained volcanic rock, among the most extensive of their kind in the world. The Northeast New Territories Sedimentary Rock Region preserves rocks spanning hundreds of millions of years, from ancient sandstones to young red beds and the finely layered siltstones of Tung Ping Chau.
Much of the geopark lies within country parks and marine parks, and most of it is reached on foot or by boat. It has become a key place for teaching geology in Hong Kong and for understanding how the south China coast was built.
How the landscape formed
About 140 million years ago, in the Early Cretaceous, a huge volcanic eruption near what is now High Island emptied a magma chamber and collapsed into a caldera. The thick ash that filled it cooled slowly and contracted, cracking into regular columns — mostly hexagonal and often more than a metre across — that are now exposed along the coast of Sai Kung. In the north-east, older sandstones and mudstones of the Devonian, Permian and Jurassic periods, and younger red conglomerates of the Cretaceous and early Tertiary, record rivers, deltas and shallow seas. Tung Ping Chau, the youngest rock in Hong Kong, is built of thin-bedded siltstone laid down in a lake. Waves, typhoons and the rising sea since the last Ice Age have cut all these rocks into a coast of arches, sea caves and wave-cut platforms.
Highlights
High Island Reservoir East Dam
万宜水库东坝
The most accessible place to see the volcanic columns up close, where the reservoir's dam meets the open sea. Cantonese: Maan Yi Seui Fu Dung Ba.
Sharp Island
桥咀洲
An island off Sai Kung joined at low tide to a smaller islet by a natural sandbar (tombolo), with volcanic rocks and a pineapple-bun-shaped weathered boulder. Cantonese: Kiu Tsui Chau.
Tung Ping Chau
东平洲
A crescent-shaped island near the mainland coast of Guangdong, of thinly layered siltstone forming wave-cut platforms and rock stacks.
Port Island
赤洲
An island of red conglomerate and sandstone, whose colour gives it its Chinese name, “Red Island”. Cantonese: Chek Chau.
Double Haven
印洲塘
A sheltered bay dotted with islands and a marine park in the north-east. Cantonese: Yan Chau Tong.
Ma Shi Chau
马屎洲
A small island in Tolo Harbour of Permian sedimentary rocks, linked to the shore by a tombolo at low tide. Cantonese: Ma Si Chau.
Plants and wildlife
The geopark's coasts and islands overlap with country parks and marine parks that protect coral communities, seagrass beds and coastal woodlands. Hong Kong's eastern waters hold a surprising diversity of hard corals, especially around Tung Ping Chau and Double Haven.
Plants
Fung shui woods
风水林
Patches of old woodland kept behind villages for feng shui, now rich refuges for native trees. Cantonese: fung sui lam.
Mangroves
红树林
Small stands of mangroves in sheltered bays of the north-east.
Wildlife
Hard corals
石珊瑚
Dozens of species of reef-building coral grow in the eastern marine parks.
White-bellied sea eagle
白腹海雕
A large raptor that nests on sea cliffs and islands in eastern Hong Kong.
Culture and legend
The coasts of Sai Kung and the north-east were settled by Hakka farmers and by boat-dwelling Tanka fishing communities, and many of their villages, now largely abandoned, lie within the geopark. Some, such as Lai Chi Wo, are being revived as places of heritage and sustainable farming. Temples to Tin Hau, the sea goddess, stand on several islands.
Lai Chi Wo
荔枝窝
A walled Hakka village founded about three centuries ago, with a fung shui wood, restored in recent years. Cantonese: Lai Chi Wo.
Tin Hau temples
天后庙
Temples to the Empress of Heaven, protector of seafarers, on islands and harbours. Cantonese: Tin Hau Miu.
Hakka villages
客家
The farming villages of the north-east, many with walled layouts and ancestral halls. Cantonese: Haak Ga.
History
c. 140 million years ago
High Island supervolcano erupts
The caldera fill that later cools into the Sai Kung columns is laid down.
1978
High Island Reservoir completed
The dams built to close off the sea channel expose the columns to view at the East Dam.
2009
Hong Kong National Geopark
Established as a national geopark, bringing the coastal sites under one scheme.
2011
Global Geoparks Network
Admitted to the global network, with UNESCO designation from 2015 when the label became a UNESCO programme.
Through the seasons
Spring
Warm and often foggy or hazy, with calm seas; a good time for island walks.
Summer
Hot, humid and wet, with typhoons that can halt boat services; swimming and sea kayaking are popular on calm days.
Autumn
The best season: dry, clear and warm, with calm seas and good visibility.
Winter
Cool and dry with strong north-east monsoon winds that can make boat trips rough.
Routes and ways in
East Dam of High Island Reservoir
Reached by road through Sai Kung East Country Park and on foot along the reservoir; also passed by stage 1 and 2 of the MacLehose Trail.
Sharp Island tombolo
A short walk across the sandbar at low tide from the main island to Kiu Tau, with volcanic rock formations at each end.
Tung Ping Chau coastal walk
A circuit of the island along its rock platforms and cliffs, a few hours on foot.
Lai Chi Wo nature trail
A walk from the village through fung shui woods and mangroves along the shore of Double Haven.
Practical notes
- Many sites are reached only by boat or on foot; check sea and weather conditions, as typhoon and monsoon signals suspend boat services.
- Hammering, collecting rocks and climbing on fragile formations are prohibited in the geopark.
- Coastal paths are exposed to the sun with little shade; carry water, sun protection and sturdy shoes.
- Sai Kung town is the gateway to the volcanic rock region; the Hong Kong Geopark visitor centre is in Sai Kung.
Frequently asked questions
Sources
- UNESCO Global Geoparks — UNESCO (retrieved 27 September 2026)
- Hong Kong UNESCO Global Geopark — Agriculture, Fisheries and Conservation Department, HKSAR Government (retrieved 27 September 2026)
- Country and Marine Parks — Agriculture, Fisheries and Conservation Department, HKSAR Government (retrieved 27 September 2026)
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