Vietnam.  Exploring Limestone Monoliths of Hạ Long Bay

Featuring hundreds of stone monoliths that rise from glistening green water, Vietnam’s Hạ Long Bay is the world’s most impressive example of marine-invaded karst topography.  Located in the Gulf of Tonkin, near Vietnam’s northern border with China, the 1,553 km2 bay is the result of limestone rock being subjected to a warm climate and sea levels that have risen and fallen over the last 20 million years. 

Hạ Long Bay’s most prominent features are its 1,600 islands.  Reaching heights of a hundred meters, they are remnants of ancient sedimentary rock that has been uplifted and sculpted by water.  The ocean continues to impact the islands as seen in deep notches at water level that surround each island.  Because of their steep cliffs, most of the islands are inaccessible to humans.  Indeed, fewer than 40 are inhabited and only about half have been named. 

A local legend suggests that the islands were formed when gods sent a family of dragons to defend Vietnam from invaders.  To repel enemy ships, the dragons spat out pearls that formed a wall of islands.  Subsequently, the bay was named “hạ long,” meaning “descending dragon.”  Today, most of the 1,500 people who reside in the bay are involved in fishing or tourism.  More recently, Hạ Long Bay has been recognized as Vietnam’s foremost scenic and geologic area.  In 1962, Hạ Long Bay received special recognition by the Vietnamese Government as a Renowned National Landscape and in 1994 the bay and surrounding area became a UNESCO World Heritage Site.

My journey to Hạ Long Bay began 165 kilometers away, in Vietnam’s capital city of Hanoi.  Traveling by private car, the three-hour journey took us past rice paddies and through towns and industrial areas.  On our arrival in Hạ Long City, we were directed to our own personal tour boat.  With an overcast sky and cool February temperatures, we bundled up for riding on the open-air upper deck.  Shortly after departing, our captain stopped at a floating village so his staff could purchase lunch provisions of fresh fish.  Soon after leaving the harbor, we passed Hon Ga Choi, dubbed “Kissing Chicken Rock,” and several other small islands topped with thick layers of subtropical vegetation.  Although most islands are small, a few sustain populations of deer, monkey, and antelope. 

Our delicious meal of steamed crab and prawns was served in the boat’s main cabin.  After lunch we disembarked at Đầu Gỗ Island to tour a grotto (cave).  The largest cave in Hạ Long Bay, Đầu Gỗ Grotto was described as “Cave of Wonders” in the 1938 French travel book, Merveilles de Monde.  Đầu Gỗ is also called the “End of Wooden Bars” cave because wooden columns found in the cave are believed to have been put in place to sink ships carrying Mongolian invaders during the 13th century. 

From the dock we climbed 90 rock steps to reach the natural entrance.  Formed approximately two million years ago, the cave has outer, middle, and interior chambers featuring stalactites, stalagmites, and other precipitative features that are illuminated by bright colored lights.  Following our cave tour, we returned to Hạ Long City for our drive back to Hanoi.

If you are interested in learning more about Vietnam’s national parks, please see my co-authored article: Vietnam's Emerging National Parks: War, Resource Exploitation, and Recent Struggles to Protect Biodiversity (© 2013 American Geographical Society).