You can only place one tile per layer. click the tilemap and click the layers dropdown. make a new one and change the z indez by 1. this will be your props layer. whenever you want to place something not walkable, click the layers dropdown and select the one you just made.![](https://godotforums.org/assets/files/2023-11-20/1700494442-70704-screenshot-2023-11-20-103249.png)
![](https://godotforums.org/assets/files/2023-11-20/1700494442-138047-screenshot-2023-11-20-103254.png)