Gplace
Geological Formation
The striking black boulders at Koh Kham are basaltic volcanic rocks, remnants of an ancient crater active millions of years ago. The process began with a volcanic eruption, where molten magma rose and surfaced as lava. Upon contact with air and seawater, it underwent rapid cooling, solidifying into dense, dark rock.
Over millennia, erosion and weathering from wind and tides wore down the volcano's structure, leaving only these durable boulders scattered across the shore. As sea levels stabilized, coral growth flourished around the submerged rocks, creating the "underwater garden" seen today.