Hong Kong Toursim Board

A blue, anchor-shaped monument beside East Dam, next to the beautiful, rolling hill-flanked 6.67 sq km reservoir, marks the start of the trail. The route, which loops along the side of the Pacific Ocean-facing East Dam and its protective breakwater, offers impressive Instagram-worthy views of the reservoir, dam and breakwater dolosse, or double T-shaped concrete wave breakers, and — out to sea — exposed rock columns along the side of the triangular sea stack, Po Pin Chau, which has been separated from the Fa Shan headland by sea erosion.

This 1 km-long extension to the trail leads uphill to Biu Tsim Kok viewing point, which offers 360-degree views of the reservoir, Po Pin Chau sea stack, Ung Kong Group, Ninepin Group and spectacular Long Ke Wan, known for its idyllic, gently curving bay, crystal-clear waters and unspoilt beach of fine white sand.

The stunning, light-coloured rock columns found in the Geopark’s Sai Kung Volcanic Rock Region — created as dense volcanic ash and lava cooled following massive eruptions 140 million years ago — are estimated to cover an area of more than 100 sq km — including some located underwater. Those that are visible rise up to a height of 100 metres and have an average diameter of 1.2 metres.

This geological feature — a fracture zone of hexagonal rock columns is easy to miss when you are admiring the cliffs covered in numerous hexagonal columns. Luckily the information boards along the trail will help you spot one. A fault breccia belt is created when the hexagonal columns along a fault line are broken into fragments during a tectonic movement.

The trail takes you past one rock face featuring an area of distorted, S-shaped columns, as if they have melted in the sun. This area of hexagonal rock columns were twisted — by the effects of a geological movement — before the rock columns completely solidified. Some years later, hot magma was able to force its way between the weakened columns and spread across the top of the columns, forming a dyke as it turned to dark coloured rock.

A wooden walkway at the end of the trail takes you near the entrance to a sea cave, which looks slightly out of place below East Dam. This area — originally part of the narrow waterway running along the fault line between High Island and Sai Kung Peninsula — was blocked off to form the reservoir. The cave was created, slowly over time, as waves wore away the coastline’s softer rock.