Baldur's Gate: Enhanced Edition

Chapter 8 - Coast Way Crossing (starting area)

Forewarning: Getting this achievement made it impossible for me to actually complete the quest, so ignore the menhirs when you start and wait until you found them all. Save, get the achievement, load, now do the quest correctly.

East of the camp you find a woman next to a large stone object. Talk to her, accept the quest about the ancient menhirs. All 6 of them are found in this map. Use a low-charisma (<10) character to fail the singing-challenge at every single menhir (Minsc work for this). Beware summoned monsters / instant damage for that character.

At the last menhir (in the north / northwest, next to stone statues) you will also sing, after which the menhir will ask you a question: Pick a wrong answer (the correct one is "The wind blowing in a tree next to a river."). Afterwards, the achievement should unlock.

Important note: Failing that specific menhir singing and giving the correct answer is one of the requirements to obtain the achievement Riddlemaster, later on. Singing successfully at all menhirs except the last one with the riddle is viable to complete the quest.