Here is the full list of all 6 Monuments Flipper: Prologue achievements. It takes around 2-3 hours to unlock all of the achievements on Windows.
Complete all main quests on the Aqueduct
Complete all tasks in the prologue.
Order the parts and build a wooden cantilever.
Rebuild the Roman Crane.
Complete main task in Old Village.
Find all spear pieces, restore and reassemble.