Hạ Long Bay
Limestone Mountains are unique rock formations in Halong Bay in Vietnam, creating amazing natural environment.
Halong Bay is home to some of the world’s most stunning landscapes, most of which can be attributed to the amazing rock formations that dot the bay’s topography.
More than 500 million years ago, Halong Bay began to take shape. The incredible natural wonder that is the bay today is the consequence of innumerable changes over time. The stunning ancient sea limestone boulders formerly reached heights of more than a kilometer. Erosion over millions of years has shrunk them to their current size.
Halong Bay as we know it now was developed during a time in Earth’s history known as “The Middle Holocene Transgression,” say scholars and credible geologists. The term “marine transgression” is used to describe an era when sea levels were significantly higher than they are now, making shorelines even higher and causing widespread flooding.
Like the iconic limestone karsts that rise up from the bay’s waters, the terrain around Halong Bay is predominately composed of thick limestone. Halong Bay’s limestone was initially deposited during the Carboniferous, some 340 million years ago. Large swamps contributed to the transport of carbonate sediment into the oceans at this time, when Earth was warmer and wetter than it is now. Over a period of many millions of years, this led to the limestone gradually hardening and thickening. Today’s well-known karsts are the result of this limestone reaching a thickness of 1,200 metres.
The rain and the water have been eroding the land for millions of years, creating Halong Bay’s spectacular network of tunnels and valleys. The earliest of these caves, known as “Phreatic Caves,” are often located on the cave’s upper levels. Among these Phraetic caverns is the well-known Sung Sot Cave, also known as the “Surprise Cave.” Sung Sot is among the largest and most impressive of Halong Bay’s caverns.