Koh Samui/Things to do/ viewpoint
Hin Ta and Hin Yai
The Grandfather and Grandmother rocks at the south end of Lamai, a fifteen-minute stop that most Samui itineraries include and nobody spends an afternoon at.
What we checked, 15 September 2026
Existence and coordinates confirmed on OpenStreetMap on 15 September 2026. No guest score exists for a rock formation and we have not invented one. We have not been.
Verified via. OpenStreetMap, checked 15 September 2026, recorded as a tourism attraction at 9.4518, 100.0390 under the Thai name หินตาหินยาย.
Admission
OpenStreetMap records no admission charge, but has no fee tag either way, so we are not calling it free. We have not verified on the ground whether parking is charged, which at Thai roadside attractions it often is.
Two rock formations at the southern end of Lamai that resemble human genitalia closely enough that Thai has named them the grandfather and the grandmother. Nearly every Samui itinerary includes them and nearly everybody stays about fifteen minutes.
What this listing is and is not. There is no guest score here and there never will be, because nobody rates a rock on Booking.com. A tour operator’s rating for a trip that stops here is a rating of the trip, not the place, and putting it on this page would be dishonest. So this page tells you where it is, what we confirmed, and what we could not.
What we confirmed: OpenStreetMap records the formation at 9.4518, 100.0390, as a named tourism attraction, checked 15 September 2026.
What we did not: whether anything is charged. OpenStreetMap carries no fee tag, which means unrecorded rather than free, and Thai roadside attractions frequently charge for parking even where entry is free. Budget a small amount and do not be surprised.
The honest assessment is that the rocks are a photograph and the walk down to them is the better part. The coastline here is rocky and dramatic in a way the sand at Lamai proper is not. Expect to run a gauntlet of stalls selling coconut sweets on the way through, which is part of the experience and mildly relentless.
Best for
A short stop with a genuinely good stretch of coast attached
Skip if
You are expecting an attraction, this is two rocks and a gauntlet of stalls
Where it actually is
Lamai Beach, Maret, Koh Samui 84310
Lamai, Koh Samui
Map data © OpenStreetMap contributors.View larger map
More in Koh Samui
- Samui Elephant Home — wildlife
- Tree Bridge Zipline Samui — nature
- Big Buddha and Wat Plai Laem Half-Day Tour — culture
- Ang Thong National Marine Park — water