On Sai Kung’s coast, Hong Kong Geopark identifies a volcanic-rock region known for striking hexagonal columns. Their repeated sides form a natural geometry across the cliffs, where erosion exposes the rock’s structure. The columns are part of a geological landscape, not a human-built wall.
From the journal
Hexagonal Columns on Sai Kung’s Volcanic Coast
Sai Kung’s volcanic-rock region is known for extensive fields of hexagonal columns, distinct from the sedimentary landscapes of the northeast.
In this district · Sai Kung ↗A coast shaped by volcanic rock
A different geology in the northeast
The Geopark also includes the Northeast New Territories Sedimentary Rock Region. Its layers range from Devonian sandstone and conglomerate, around 400 million years old, to Paleogene siltstone, around 55 million years old. The volcanic columns of Sai Kung and the northeast’s sedimentary layers belong to distinct geological settings.
Reading the geopark as a landscape
Hong Kong Geopark links geoconservation, education and sustainable geotourism. The columns offer a clear visual introduction: repeated forms meet a coastline shaped by erosion. Seen alongside the sedimentary rocks farther northeast, they reveal how a compact territory holds more than one geological history.