Invasion

Invasion is a mosaic collection in Dragon Age: Inquisition. "Pieces of an old Tevinter mosaic are scattered across the Dales. If recovered, they could be reassembled."

Acquisition
Triggers when any mosaic piece from this collection is found.

Walkthrough
The mosaic pieces are found around the Dales in the following locations:

Emerald Graves
 * One piece in the Veridium Mines
 * One piece in the personal store room (adjacent to the study) in the Villa Maurel. A warrior is required to break the wall
 * One piece in Argon's Lodge. It's in a room next to a log pile with a table that has weapons on it in front
 * One piece in Chateau d'Onterre. It is on the left-hand wall to in the locked room off the Grand Balcony
 * One piece on a balcony in the Chateau d'Onterre. You need to jump out of a window onto a ledge then jump to the top of a nearby building (Piece 12)
 * One piece outside the door at the Din'an Hanin landmark
 * One piece inside of Din'an Hanin.

Exalted Plains
 * One piece in the final chamber of Unadin Grotto.
 * One piece at the Ancient Baths. It is behind a wall that requires a warrior to break, and is found on a pier. (Piece 1)
 * One piece at the entrance to The Dead Hand. It's on a rock behind the Landmark
 * One piece in The Dead Hand (cave). It's on the left-hand side of the main room
 * One piece directly east of Lindiranae's Fall, in the rocks overlooking Riel. (Piece 8)

Rewards

 * 50 XP for each mosaic piece
 * 200 Influence for collecting all 12 pieces

Results
The recovered mosaic can be seen on the northwest wall of the Skyhold main hall. If you're facing the door near Gatsi, it's on the wall you face if you turn 90o to the left.

Recovering every piece of the mosaic and letting Gatsi translate it unlocks Codex entry: The Mason's Tales: Invasion.