Which unsolved puzzle fascinates you and why

The greatest mysteries and riddles in the world


What we cannot explain to ourselves, what we have no answer to, what makes us shudder and astonish, that is what interests us and generations before us most. That's why people love crime thrillers and detective series and probably also escape rooms. Finding the solution to a question, puzzling and following clues: all of this makes one good puzzle out. In this blog we have selected such mysteries for you that no one has solved yet and that still raise questions all over the world.


The Buzzer - UVB76

This is a radio station on the frequency 4625 and 4810 kHz. A signal was received here for the first time in 1973. A short “buzz” a hum that can be heard around 25 times per minute. Every now and then the signal is interrupted and Russian numbers can be heard. Occasionally, short parts of conversations in Russian can also be heard.

An example of such an interruption looks like this:

On December 24th In 1997 the following was transferred:

Ya UVB-76, Ya UVB-76. 180 08 BROMAL 74 27 99 14. Boris, Roman, Olga, Mikhail, Anna, Larisa. 7 4 2 7 9 9 1 4

Again and again there were anomalies in the transmission: interruptions, screams, conversations, even parts of Tchaikovsky's “Swan Lake” were played once.

What exactly is behind this remains a mystery. It is noticeable that in 2020 the buzzer is often interrupted, a Morse code or a disturbance can be heard more and more often, which probably originates from a 3 group.

Who was Jack the Ripper?

Everyone knows his name, but nobody knows who he really was: Jack the Ripper. The name of the most famous serial killer in London can be found in some letters that the mysterious woman killer is said to have sent to the police. But whether these are actually from him is questionable and in no case has been proven. He killed and mutilated 5 women in 1888 without being caught and without ever revealing his actual identity.

Oak Island piracy

Allegedly a treasure can be found on the small island off the coast of Canada, which the pirate Captain Will Kidd is said to have buried there. He lived in the 18th century. Since then it has been searched for again and again with expeditions and extensive excavations - so far without success.


The strange stone circle in Salisbury Plain, England, has puzzled historians and conspiracy theorists for centuries, because: the enigmatic stone formation is said to be 5000 years old and formed between 255-3000 BC. The huge stone formations come from a mountain range over 300 km away. Considering the size and weight of the stones, it is unbelievable how they should have got there. Each of the stones weighs almost 6 tons and they are stacked on top of each other. Technically and physically an unbelievable achievement!

The exact meaning has not yet been clarified and is still a mystery. Many different theories are represented here, from the legacy of aliens to random glacier structures to healing sites. The most common, however, is that it is a burial site, since cremated remains near the complex could be compared with the date of origin of Stonehenge.

Nazca lines

These are so-called GEOGLYPHS, i.e. ground signs, which in this case can be found in southern Peru in the Nazca Desert. Some of them are just simple lines, but others represent figurative forms and some are more than 1 km wide and long. It is believed that they have a religious meaning, or should serve as astronomical signposts, and that they were man-made. However, if you see these structures from an aerial perspective, you can't help but be amazed and it's hard to believe that they were actually made by human hands.

Maya calendar

Who of you was there on December 21, 2012 when the world was going to end according to the Mayan calendar? The mysterious calendar that scientists interpreted and that was supposed to end on this auspicious day in December 2012 was discussed everywhere at the time. The end of the world had not been foretold for the first time; it is now assumed that the calendar, which showed a calendar for a long time, namely thousands of years ago, was simply no longer used and was replaced by other systems by the Mayans.

Bermuda Triangle

The Bermuda Triangle (we don't mean that in the 1st district at Schwedenplatz) is located in the western part of the Atlantic Ocean in the Caribbean off Florida and is also called the Teufel Triangle or “Hurricane Alley”. This region is particularly exciting because planes and ships are said to have disappeared there again and again. Paranormalities were also repeatedly found. Clocks slowed after the area was traversed. Compasses were not pointing in the right direction. Although it was believed that these disturbances were due to magnetic activity, it has not been proven. Both natural and supernatural explanations should serve as the solution: UFOS or connections with the sunken city of Atlantis? The Gulf stream, methane strands or the weather are named as natural causes. Whatever affects this region of the world - it leads to questions and many conjectures.


The cited stories and unbelievable incidents are just a few. The Fascination with the unsolved however, remains with young and old and keeps us researching, thinking about and discovering.


In the Escape rooms at Open The Door Vienna we try to elicit exactly these characteristics from our players. We want to arouse curiosity and a thirst for adventure, a vigilant sense of detail and logic as well as context. We cannot contribute to the elucidation of these great mysteries and riddles in this way, but we can contribute to the solution of many a little mystery.