347

Why taps on the wall?

In one of the hotels in Dusseldorf where I had to go in the room I saw this: (the three prints)





Two:



Source:
Pictures
Hotel of plastic cards
KitAyFon from the cellars of the Middle Kingdom
"Hound of the Baskervilles" in the swamps of Devonshire
How to map the planet conquered
16 cards in the world, which is not taught in school
What do the numbers on a plastic card? (2 photos)
The most luxurious hotel in the world
Burj Al Arab - the most luxurious hotel in the world (35 photos)
Moscow hotels
Military topography
...
Hotel of plastic cards
...
KitAyFon from the cellars of the Middle Kingdom
...
"Hound of the Baskervilles" in the swamps of Devonshire
...
How to map the planet conquered
...
16 cards in the world, which is not taught in school
...
What do the numbers on a plastic card? (2 photos)
...
The most luxurious hotel in the world
...
Burj Al Arab - the most luxurious hotel in the world (35 photos)
...
Moscow hotels
...
Military topography
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