Mauthausen Gas Chamber Interior
Shown in the photo above is the door on the west wall, taken from the inside; note the back side of two latches, one that is about a foot from the top of the door and the other that is about a foot from the bottom. These latches were used to lock the door from the outside by turning the latch handles. There are no handles on the inside of the doors.
There were two doors into the gas chamber in order to provide access to the two crematory ovens which were in two different locations. Each of these doors leads to a separate morgue room and crematory oven.
The Mauthausen gas chamber was disguised as a fully functional shower room. The sign on the wall, shown in the photo above, was not there when the shower room was used as a gas chamber. The photo shows 3 of the 16 real showerheads on the ceiling. All of the "gassing apparatus" was removed by the SS guards when they left the camp before the American liberators arrived; today there is nothing in the gas chamber which indicates that it was anything more than an ordinary shower room.
All four of the major Nazi concentration camps in the Greater German Reich (Dachau, Sachsenhausen, Buchenwald and Mauthausen) had shower rooms in the crematoria buildings. Only the one at Buchenwald was used as a real shower room; the other three were homicidal gas chambers disguised as shower rooms. The Dachau gas chamber has shower heads stuck into the ceiling with no visible pipes on the ceiling.