The first time you go to retrieve a photo you previously deleted in the Photos app for OS X, you might rightly wonder where the Trash folder went. In iPhoto, deleted photos were kept in the Trash folder, which you could access from the sidebar.
In Photos, no such animal exists. Even if you show the sidebar in the Photos app, you won't see a Trash folder listed. So, where does one turn to recover a deleted photo?
It's simple, if you know where to look. Go to File > Show Recently Deleted. You will see all of your deleted photos, with the number of days remaining before each is permanently deleted. It's similar to the Recently Deleted album in the Photos app for iOS, but the Mac app features no such album on the Albums view.