by Michael Malvick (Ladybug Kids)
In July 2026, my younger daughter and I joined my brother and his family for a trip to Thailand to attend a wedding of a Norwegian cousin. The day after the wedding, American and Norwegian family members took a tour of Ao Phang Nga National Park in Phang Nga in the Strait of Malacca between the island of Phuket and the mainland of the Malay peninsula of southern Thailand. The highlight of the tour for me was visiting “Koh Panak Mangrove Hong” Earthcache (GC5TY1K).
“Koh” means “island” in Thai. A “hong” is a sinkhole that formed in the middle of the limestone island due to the rock being dissolved over time by water, similar to how limestone caves are formed. What makes this hong unique is the bottom is accessible only through a narrow passageway that is filled with water at high tide and becomes navigable as the tide falls. Our tour operator scheduled the tour so we arrived at the island just as the passageway could be swum through, but before the hordes of kayakers arrived. So, with mandatory swim noodles and flashlights (torches) in hand, we jumped off the boat and followed our intrepid guide through the passageway.
We had to be careful not to bump our heads on the sharp rocks and to look up in other places to see the surprising variety of speleothems (draperies and stalactites) growing off the ceiling and upper walls. Just as we entered the hong, the only rain of the day started falling, which was not a problem since we were all already wet from the neck down. Once inside, we enjoyed swimming and walking on the muddy bottom around the mangroves and seeing many mud skipper fish hanging out on the roots and trunks of the trees. We looked up in awe at the circle of sky above us formed by the hong’s vine and tree covered limestone walls.
Once our visit was complete, we headed back through the passage and saw that the tide had fallen enough for a group of kayakers to enter the passageway, but not quite get through, so our timing had been perfect. Photos on the cache page indicate the tide drops far enough for visitors to eventually be able to walk through passageway, leaving kayakers who tarry inside the hong too long high and dry.
With everyone successfully navigating the passageway back to the bay, we set course for “James Bond” island and lunch at a floating village.