Placing a Landmark
You may place a Landmark Token whenever you place a tile that adds a 5th or greater tile to a habitat corridor. It must go on the tile you just placed, never another tile of that corridor, and it must be a habitat you do not already have a Landmark for. You may still place this turn's Wildlife Token, but not on the Landmark tile, or return it to the bag.
Also answers
placing a landmarkplace a landmarkwhen can i place a landmarkcan i place a landmark on an older tilelandmark on the new tilefifth tile in a corridor5th tile in a corridorcorridor of fivecorridor of 5 or morelandmark placement