Unfortunately, our quick exit from the Acropolis earlier meant that we missed a few collectibles on the way out. The good news is we can head back and grab them when we feel like it. To do so, fast travel to the ‘Tower Courtyard’ Base Camp in the southern end of the map.
From the ‘Tower Courtyard’ Base Camp, follow the path leading to the west. Continue until you reach a large room after crawling beneath a half-destroyed doorway. In the center of this large room, there is an open trapdoor in the floor that wasn’t here when we were previously here.
Drop down into the trapdoor and use Lara’s pickaxe to force open the door. Jump across the small stream of water when you reach it to find a Document [10/10 - Greek] .
Enter the water and follow the passage all the way through until you reach a dead end. Crawl through the small gap on the wall to the right to enter the next area. As soon as you are through the crack, the final Coin Cache [03/03] can be found on the floor.
This should be your 100% completion in The Acropolis region. Backtrack all the way to the previous Base Camp to fast travel out of there!