This is the remains of a toilet facility built by Romans in a villa rustica in the Odenwald in German. When it was built it was most probably not an outhouse as such but now it is as open as anything.
This is from more than a millenium later, in the ruin of a castle in Handschuhsheim near Heidelberg. Since it has no direct water access (unlike the Roman facilities) it was a lot less hygienic.
This now is from the 21st century: plastic and with a slightly humourous sign.
Finally, for my private satisfaction. The poster of a local wannabe politician with a sign that shows where I think he belongs.