Most visitors never leave the harbour and the shopping districts, and it is fair to say that most of Hong Kong's own residents have not seen this either. The northeast of the territory, from the Sai Kung peninsula out through the islands, is a geological park of international significance: it became a national geopark in 2009 and joined the UNESCO Global Geoparks Network in 2011, as China's twenty-sixth and one of the few that lies inside a major city.
What makes it is a single rock type. Around 140 million years ago this area was the site of an enormous volcanic eruption, and the ash and tuff it left cooled into near-vertical hexagonal prisms. They average 1.2 metres across. The comparisons are made with the Giant's Causeway in Northern Ireland, a World Heritage site, whose columns are half that size - and unlike the Causeway, most of this field is underwater, with some two hundred thousand columns exposed on the shoreline alone.
We spend the morning at the East Dam of the High Island reservoir, where the wall cuts through the column field and a geopark trail sets out the geology in front of you; lunch is seafood in Sai Kung town; and the afternoon goes to the islands by boat, if the sea allows it.
The other Hong Kong
Northeast of the city, the Sai Kung peninsula and the islands beyond it were declared a national geopark in October 2009 and admitted to the UNESCO Global Geoparks Network on 18 September 2011, as China's twenty-sixth world-class geopark. The park covers 49.85 square kilometres of land and is one of the very few geoparks anywhere that lies inside a major metropolis. It has two regions and eight scenic areas. This day is spent in the western of the two, the Sai Kung Volcanic Rock Region.
What you are looking at
The columns are rhyolitic tuff - the deposit of a volcanic eruption on a scale Hong Kong has not seen since - and they cooled into near-vertical hexagonal prisms. They are about 140 million years old. Individually they average 1.2 metres across, which matters, because the comparison everyone makes is with the Giant's Causeway in Northern Ireland, a World Heritage site, where the columns are about half a metre. The field here covers roughly 150 square kilometres and most of it is under the sea; something like two hundred thousand columns are exposed on the shoreline. The sections on the coast of Fa Shan, at the High Island reservoir, reach a hundred metres and are described, accurately enough, as a natural hexagonal wall-painting.
Morning - the East Dam of High Island Reservoir
We drive across the peninsula to the East Dam, where the reservoir wall cuts through the column field. A geopark trail and its interpretation panels run along the water: the fault line, columns bent and twisted by later movement, a dark dyke of younger rock cutting across the columns, and, offshore, the sea stack of Po Pin Chau standing clear of the headland. Nowhere else is the structure so easy to read on foot, and nowhere else is it so easy to photograph.
Lunch - Sai Kung town
Back down to Sai Kung for lunch on the waterfront, where the tanks hold the day's catch and the restaurant chooses the fish for you rather than the other way round.
Afternoon - out to the islands
The rest of the geopark is only reachable by water. Weather permitting, we take a boat out past the Ung Kong group - Wang Chau, Basalt Island, Bluff Island - where the same rock has been cut into sea caves and sea arches by the swell. Four of them are named: the Oan Min Kok cave at about forty-five metres, Wang Chau Kok at thirty, Sha Tong Hau at twenty-four, and the arch at Conic Island. The sea cliff on the southeast coast of Sha Tong Hau Shan falls 140 metres, the highest in Hong Kong. Further out, the columns of the Ninepin group are the largest in the park, over two metres across. If the sea is up, the boat is not worth attempting and we spend the afternoon on the peninsula instead: the tombolo at Sharp Island, which appears only at low tide, and the lookouts above the bay.
Meals
Lunch (seafood, at Sai Kung)
Accommodation
Day programme - no hotel night included.
| Group Size | Adult(Age:8-80) Price/p.p | Child(Age:4-7) Price/p.p | Infant(Age:0-3) Price/p.p |
| 2 PAX | from $434 | / | / |
| 4 PAX | from $246 | / | / |
| 6 PAX | from $186 | / | / |
| 8 PAX | from $155 | / | / |
| 10 PAX | from $136 | / | / |
| 20 PAX | from $105 | / | / |
| 30 PAX | from $86 | / | / |
One practical warning. The second half of this day is on the water, and the boat is the part we cannot promise. In a strong swell or under a typhoon signal it does not run, and we will not put guests on it in those conditions. On those days the morning at the East Dam still stands - it is the best place in Hong Kong to read the geology on foot - and we use the afternoon on the peninsula instead: the tombolo at Sharp Island, which surfaces only at low tide, and the lookouts above the bay. Bring sun protection and shoes with grip; there is very little shade on the dam.
Q: Is this tour private or shared?
A: It is a private tour. Only your own party travels with the guide and vehicle, so the pace and the order of stops can be adjusted on the day.
Q: What is the best season for this itinerary?
A: April to June and September to November bring the mildest weather and clearest light. The programme runs year round, and we adjust the daily timings in mid-summer and winter.
Q: Can you handle dietary requirements and accessibility needs?
A: Yes. Vegetarian, halal, gluten-free and allergy-aware menus are arranged when you tell us in advance. Step-free and low-mobility versions of the route can also be planned.
Q: How do we book and pay?
A: Send us your travel dates and group size for a same-day quotation. A deposit confirms the booking, the balance is due before arrival, and prices are guaranteed for 7 days.