We visited Glasgow (Scotland) last summer and the hotel fire alarm went off the middle of the night (for whatever reason we seem to attract fire alarms while on family holidays)
After getting the kids dressed(ish) we exited the rooms, totally missing that there was one emergency staircase immediately opposite. There was a sign at ceiling height, at 90 degrees to us, which was basically invisible. There was no sign on the door to the staircase itself :/
So, we went all the way down the hall, along with a bunch of other guests, then I carried my 7 year-old down seven floors' worth of the secondary staircase stairs to the ground floor, really pretty slow progress due to the number of people, on exiting the building we met four fire engines plus a significant police presence, and hundreds of hotel guests. Turned out it wasn't a fire, but a disturbance, and a fire alarm had been activated as part of that. We were outside for ages.
Lesson learned: just as you hopefully do immediately after boarding an aircraft, check your exit routes well before you need them...