After you reach Parfum Palace, you can enter Palais Lane from the west side to reach a previously inaccessible area.
Battle and Catch
In the tall grass, you can encounter Kecleon, Honedge, Oddish, Espurr, Nincada, Sentret.
When you first enter the west side of Palais Lane, you encounter Poké Fan Family Jan & Erin. They do a double battle using two level 14 Furfrou, each with different fur styles.
Go west through the grass past the Poké Fan Family. There is a short incline past the grass where you can get a Super Repel.
South of there, there is a hidden trainer in the grass. If you walk past, the trainer will come out and challenge you. It's Beauty Brigitte. She has a level 12 Espurr and a level 12 Butterfree.
Walk east from the Poké Fan family through the grass to find an Awakening.
South of the Poké Fan family, you can find an Aguav Berry tree.
South of the Aguav Berry tree, you find Youngster Tyler. He has a level 12 Venipede and a level 12 Scraggy.
South of the youngster and a little to the east, Backpacker Roderick is in the grass. He has a level 14 Bunnelby.
Southwest from the Backpacker is an Ultra Ball past the grass.
From here, you can go east to return to the middle of Palais Lane, where you can go north to Parfum Palace or south to Rivière Walk.