Koh Hong

Koh Hong is a limestone island in Phang Nga Bay, inside Ao Phang Nga National Park, built around a lagoon reached by kayaking through a narrow cave passage under the cliffs. Foreign entry to the national park is 300 THB for adults, 150 THB for children, and the park is officially open daily 08:00-16:30 during the October-to-May season. It’s the second most-visited stop in the park after James Bond Island, and it’s a genuinely different Koh Hong from the one near Ao Nang in Krabi. Check which national park your tour is booked into if the name alone is all you’ve seen.

The lagoon is the reason people come. Paddling in through the sea-level cave opens onto a sheltered pool ringed by limestone walls, calm enough that even nervous swimmers relax once inside. Getting the tide window right matters: the passage is only navigable a couple of hours either side of low tide, so a tour that shows up at the wrong time either can’t get you in or has you scraping the kayak roof against the rock. Beyond the main lagoon, smaller karst islets nearby create narrow canoeing channels between them, and a coral fringe around parts of the island gives a reasonable snorkel if the boat schedule allows time for it.

Watch out: most visitors arrive as part of a multi-stop Phang Nga Bay tour that allocates 30-45 minutes at Koh Hong, enough for the lagoon paddle, not much more. If the lagoon and a proper snorkel stop both matter to you, look for a smaller-group or private tour rather than the standard big-boat itinerary from Phuket.

Insider Tip: Boats leaving from Koh Yao Noi reach Koh Hong faster than the standard Phuket day-tour routes and tend to arrive before the bigger tour groups, giving a calmer first look at the lagoon.

Ao Phangnga National Park’s other karst islands, including the nearby Koh Tapu (James Bond Island), are usually stacked into the same day-tour itinerary as Koh Hong, worth checking what else your boat covers before booking separately.