The serious issue about visits to tower is that most ATC units are damn busy and have little time to do the tour of all the gadgets. Most of what you see you can learn about before you get into the tower which saves time for nattering until you see something you don't recognise.
When at Bristol ATC fixed squarely next to the approach radar position was a small red button marked "Panic". I paused and took a careful look at it. Having seen the "Crash Alarm" red button in the tower I assumed it was a similar device until I could see the tale tale blu tack oozing out the side...
