At the south end of Lamai beach are some rock formations that are standard, if a bit sophomoric, stops on any tour of Samui. The 'Grandfather Rock' and 'Grandmother Rock' have been shaped over millions of years by wind and water to resemble human sex organs. A short narrow alley lined with souvenir stalls leads from the main road to the rocks. You actually end up on Grandmother's belly, where a crevice has been worn into the rock to form granny's legs. The Grandfather Rock, a penis shaped pillar, is about 25 metres to the south.

Despite the silliness that the stones induce, the spot is actually rather beautiful, with turquoise waters in pools among the rocks.

Naturally, the rocks are a fertility symbol for many Asians, and said to be the origin of the 'Mui' peoples.

The souvenir shops lining the alley leading to the rocks are generally nothing special.