There are no "Pétain landmarks" per se anywhere in Europe. We can probably find references to him on the monuments dedicated to the battle of Verdun in 1916, where he was the main military leader on the French side. BTW, it was because of his role during WW I that he was invited to NYC in 1931, and the plaque in question was put there on that occasion - a good nine years before Vichy. Note that most monuments to WW I & II do feature anonymous soldiers rather than generals (I was thinking of this).

Vichy is of course one of the places where one might find references to Pétain: he lived there during four years as the head of the infamous collaborationist "Etat francais" regime (the last statue of Pétain was reportedly removed from the Vichy streets only 3 years ago). Lastly, there may be some mention of him at the Fort de Pierre-Levée citadel on the Île d'Yeu, where he was imprisoned following his trial and died in 1951.