Vietnam and Cambodia
Sung Sot Cave
Hang Sung Sot was our last stop in Ha Long Bay—in fact it was our last stop in northern Vietnam before we headed to Cambodia. The islands in Ha Long Bay, as I mentioned in a previous post, are made of limestone, and limestone is readily dissolved as rainwater seeps through the islands. As a result, there are lots of caves in Ha Long Bay’s islands, from tiny impenetrable openings to vast caverns.
Hang Sung Sot is the largest of the caverns in Ha Long Bay. It was discovered in 1901 by French explorers who named it Grotte des Surprises—literally Cave of Surprises—because the cave’s small opening led to an unexpectedly large cavern. Grotte des Surprises loosely translates to Hang Sung Sot in Vietnamese.
To reach the cave, we had to hike up some 100 or so stair steps to get to the cave’s opening, some 85 feet up the island’s cliff face. The entrance to the cave is modest, large enough to comfortably walk through, but it does not hint at all at what lies beyond. Once past a small anteroom, you walk into an immense gallery of over 100,000 square feet with a ceiling that soars to over 100 feet, filled with otherworldly formations of all manner of shapes and colors.
Here are some photos:
Look close! Check out the shapes and the colors!
Two stalagmites and a column, all as large as tree trunks.
This is a huge cavern!
Sometimes the colors are subtle.
Sometimes the colors are vivid and varied. The colors are defined mostly by the elements that are present and what oxidation state they’re in, but could also be influenced by a surface crust of bacteria or algae in moist caves—and this cave definitely qualified as moist! The golden yellow of this column and its cauliflower-shaped formations is probably from dilute iron (as Fe3+), but could also be a bacterial crust. I’m more intrigued by the blue in the wall. I thought it might be something exotic, but several sources online suggested it was light scattered by suspended crystalline calcium carbonate (limestone, in other words) in the water seeping down the wall. No matter the cause, sometimes the colors were striking!
At the far end of the cavern from the entry, I saw this pond overhung by turquoise and pinkish formations. The water in the pond was crystal clear. And this photo doesn’t do the pond's size justice—it was way bigger than it appears here. I’d guess it was about 30-40 feet across.
Here we’re looking toward the entry/exit—you can see how small it is compared the size of the cavern. I had stepped out of line to a viewing platform mostly to get this shot, but also because I needed to take a break from the slow-moving line of people headed to the exit. It is insufferably hot and humid in Hang Sung Sot and I was dripping wet. The climate in Ha Long Bay is hot and humid to start with and inside the cave there is no ventilation—all of the air in the cave has to come in and out through that single small entry/exit opening. It was stifling in there!
This shot looks out over the small harbor at Hang Sung Sot from the exit of the cavern. Even though it was hot and humid outside, it felt so refreshing to feel the gentle breeze there!