This guide explains how to get Former Glory achievement.
Former Glory Achievement Guide
Disclaimer: You need to have caravan town to do this achievement.
So for this it says something along the lines of "the four pieces united" witch isn't that help full I myself have this achievement and this is how to get it.
First you need the metal detector from caravan town it will glow with all bulbs on it if you are on top of treasure.
Second you will need to dig with a shovel on this spot,remember ii is not guaranted that it will be a tiki piece
Third after doing this (on islands,small island gives 1 treasure per island and giant islands give. For a while you will get 4 tiki totem pieces, they need to be placed on each other in a specific order,you can use my image or you can look on their forhead and bottom,match the colours (if there is no colour on top / bottom then it top / bottom piece) and then it will spin if you did it right and you will get the achievement,also pick up the tower for a secret item.
Upon picking up the totem you will get a tiki mask.