Thang Hen Lake
A chain of karst lakes that drain and refill on their own, connected underground and named for a bee's tail.
Saved in this browser only - no account, nothing sent anywhere. See your map
Thang Hen is a group of connected lakes in a karst basin east of Cao Bang, sitting between limestone walls with forest on them, and their behaviour is the interesting part: they are fed and drained through underground channels in the rock, so the water level changes markedly through the year and at times some of the lakes empty almost completely, refilling when the system delivers again. The Tay name is usually given as the tail of a bee, from the shape. Rafts and boats run on the main lake when it is full. The site is part of the Non Nuoc Cao Bang geopark.
What you actually see
- Lakes connected underground - fed and drained through the rock.
- Levels that change sharply - some emptying almost completely.
- Limestone walls and forest - the basin around them.
- Rafts on the main lake - when there is water.
When to go
August to November, when the lakes are fullest. Half a day.
Honest expectations
In the dry months the lakes can be very low or dry, which is the main risk of the trip. Facilities are basic. Boats operate only when levels allow. The road in is winding.
Nearby
Cao Bang is west; Nguom Ngao and Ban Gioc are north-east.
What to pack for Thang Hen Lake
Chosen from what this place is for. Tap a kit for the full checklist.
Opening times, ticket prices and seasonal closures change - check the official source before you go: official site.
