Floods in Prague in 2002, the municipality decided which part would go under water. They were terrified that the center would not be flooded - more precisely, the area of the Old Town Square and the adjacent streets.
HardRockCafé Prague is also located in the area.There is also a Jewish cemetery nearby, said to have many more bodies buried there than officially reported.

They preferred to let the densely populated part of Prague - Karlín - sink

There is another "Prague" underground under Prague. A city under a city, hidden in the mud. The question remains what or who is there. If something lives in there, it might want to climb out, right? And I don't mean mice..

Do not enter the underground in the center of Prague without protected sensibilities!!!

https://www.arfa.cz/nacist...

Just a thought, about Prague again...
Years ago, when the Charles Bridge https://www.izdoprava.cz/j... was being repaired, I remember how it was discussed everywhere what kind of space they were building right in the Charles Bridge from the Old Prague side (that is, from the center of Prague). There were tarpaulins that could not be seen through, however some in the film industry claimed that it looked like someone was building an apartment or some kind of premises below the bridge. I read many discussions about it on the Internet at the time. Today, you can practically find nothing about this "mystery" on the Internet.
It would be even more interesting to check how many other young people or children have gone missing in this area, near the Charles Bridge...
https://www.ahaonline.cz/d...

Nevertheless, today I was interested in an article about the anniversary of the Charles Bridge since its foundation, 666 years.

Just for today's shooting a student in the Faculty of philosophy in Prague. https://www.npr.org/2023/1... The circled area is the place where young people, especially girls, usually "get lost" at night. It's no secret that this area of old Prague has another "city" underground, that's why the Karlín area (Prague 8) was sacrificed during the floods in 2002 and the water was diverted from the Prague old centre (Old Town Square and surroundings up to the Charles Bridge), there to Prague 8.
Marked addresses are closed areas today due to:
Faculty of philosophy - shooting
Valentínská street - reported bombshell
City Library - Suspected Bomb (By the way, the library building is a solid labyrinth). Especially the section of old books that is closed to the public, only for approval - I was there, I needed an original of Mozart's Don Giovanni for a film. They're guarding the place like some kind of research lab.