This achievement is 5G.

These do not show up on your map but are not difficult to find as they glow white like other treasures. Using your Eagle Vision will make them even easier to see. The achievement will unlock when you pick up the last statuette.

Note: Although it isnt a requirement of the achievement, there are four pedestals along the sides and back of the villa where you can place the statuettes in pairs. Once you have gathered all 8 statuettes, place them upon the pedestals. They will then open up to reveal 2,000 each.