Star Trek: 10 Secrets Of The Next Generation Main Bridge
3. The Head
Star Trek V: The Final Frontier famously featured the only appearance of a toilet aboard a Starfleet vessel and Star Trek: Deep Space Nine made the occasional reference to "waste extraction" (whatever that is), but restrooms have mostly gone unseen in the Star Trek Universe.
However, the bridge of the Enterprise-D did have a bathroom... at least some of the time.
The Enterprise-D bridge set featured six doors around its circumference: Two led to turbolifts, another led to the dedicated battle bridge turbolift, another led to Captain Picard's ready room, and yet another led to the observation lounge. All five of these doors were used by the command crew throughout Star Trek: The Next Generation, but the sixth door was only ever shown being used by background actors.
Located directly across from the observation lounge at the rear of the bridge, this sixth door was labelled "Conference" until some time in TNG's seventh season when the signage was changed to "Head", aka the bathroom.
According to illustrator Rick Sternbach's blueprints of the Enterprise-D there was indeed a small bathroom behind that door, complete with two sinks and a toilet. But just one.
