Probably all the Linux systems are released with a set of default wallpapers. For example, Canonical organizes a contest for each release, permitting the users to submit wallpapers.
Also, Fedora includes a wallpaper pack, but this does not mean that the users cannot install extra wallpapers. They are different with each desktop environment, but the users can easily get the wallpapers created for other desktop environments.
Install the GNOME wallpapers on Fedora 23:
$ sudo dnf install f23-backgrounds-extras-gnome
Install the KDE wallpapers on Fedora 23:
$ sudo dnf install f23-backgrounds-extras-kde
Install the XFCE wallpapers on Fedora 23:
$ sudo dnf install f23-backgrounds-extras-xfce
Install the MATE wallpapers on Fedora 23:
$ sudo dnf install f23-backgrounds-extras-mate