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East Dam of High Island Reservoir

Rock-column Palace (Half-day course)



The High Island Geo Trail at the East Dam of the High Island Reservoir is an appealing route, offering beautiful vistas of the reservoir and the surrounding verdant hills, as well as magnificent hexagonal volcanic rock columns. This easily accessible scenic spot is among Sai Kung’s most popular natural attractions. It is also an ideal location for observing the world-class hexagonal rock columns at close range.

Visitors will find interpretation plates and picnic facilities along the High Island Geo Trail, which is a generally level and easy trail, suitable for all hikers. This idyllic country course winds along sheer rock cliffs, with giant columns plummeting up to a hundred feet to the ground. The visitor’s gaze takes in the beautiful coastline, which stretches for miles, and endless clusters of tall rock columns, revealing the genius and grandeur of nature. The newly opened Biu Tsim Kok extension of the geo trail offers a panoramic vista across the ancient High Island caldera, the delightful Long Ke Wan, and the idyllic High Island Reservoir.

The hexagonal columnar rock formations in Hong Kong are products of devastating volcanic eruptions about 140 million years ago. They were formed in specific conditions when masses of scorching molten volcanic materials underwent condensational contraction. They are different from hexagonal rock columns found elsewhere in both rock texture and chemical composition, making them globally important geo-wonders. They are also vastly distributed and occur in large diameter.
Looking toward the sea from East Dam, Fa Shan is cut into two parts; the one being separated is Po Pin Chau, which is a type of the sea abrasion landscapes - sea stack. Po Pin Chau was once part of Fa Shan, but years of wave impact and erosion separated it. The rock stacks on the shore of Po Pin Chau tower almost vertically over the sea. The rock face looks just like a giant pipe organ.
About 140 million years ago, when the columns were still in a semi-plastic state, they were distorted into an S-shape under the influence of earthquakes and regional subsidence. The distorted area of the rock columns is the most vulnerable. During geological processes, magma intruded along the weak line of the columns and cooled to form an intrusive dyke, which is about 40 million years younger than the surrounding rocks.
Rock columns elsewhere are usually made of dark grey basalt with low silica content. By contrast, the rock columns in Hong Kong are light-coloured, silica-rich, rhyolitic volcanic rock. The columnar joints are mainly pentagonal or hexagonal. It is estimated that the columns cover an area of over 100 km2 (including submerged areas), with an exposed height up to 100m, a total thickness of 400m and an average diameter of 1.2m. The rock columns have features of both tuff and lava, but there is still no consensus among geologists on the material that formed them.



Half-day Trip to High Island Reservoir


How to get there:

Join a Local Tour

You can book the East Dam Half-day Tour at the Volcano Discovery Centre . Round-trip itinerary is available. For enquiries, please contact the Volcano Discovery Centre (tel: 2394 1538)

By Bus

Take bus no. 94 departing from Sai Kung town centre or bus no. 96R departing from Diamond Hill MTR station (weekends and public holidays only) and get off just after Pak Tam Chung. Walk along Tai Mong Tsai Road to the junction ahead. Turn right on Sai Kung Man Yee Road and walk about 9 km

By Taxi

Take a taxi from Sai Kung town centre or Pak Tam Chung to the geo-trail at the East Dam, High Island Reservoir


By Minibus

Take a NT Green minibus #No. 9A at Pak Tam Chung to the East Dam of High Island Reservoir.
Service Hours: 9:30 a.m. - 6:40 p.m. (Every Sunday and Public Holidays).
Frequency: 20 (min). Fare: $11.3

with effect from 10 October 2021 (Sunday)

*Services will be adjusted due to bad weather. Latest information will be announced on the Facebook of the minibus company.


Take a NT Green minibus #No. 9A at the East Dam of High Island Reservoir back to Pak Tam Chung.
Service Hours: 10:00 a.m. - 7:00 p.m. (Every Sunday and Public Holidays).
Frequency: 20 (min). Fare: $11.3

with effect from 10 October 2021 (Sunday)

*Services will be adjusted due to bad weather. Latest information will be announced on the Facebook of the minibus company.




How to Explore East Dam of High Island Reservoir


travel route

Download the Above Route in PDF




Video of High Island






Key of Attraction

Don't forget to take your time to visit them !!


Reservoir Monument

History of Reservoir

Geopark Monument

Hexagonal Rock Columns

Po Pin Chau (sea stack)


S-shaped Hexagonal Columns

Sea Cave


Long Ke Wan

Viewing Point

Volcanic Rock Wall



Location Map of High Island




Enjoy Your Geopark Journey.



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Last Review Date : 8 October 2021