Is there something special to this place ? Is this a grave ? Are there any signs giving behavior rules as may be seen in some churches ? No common sense justifi

Is there something special to this place ? Is this a grave ? Are there any signs giving behavior rules as may be seen in some churches ? No common sense justification was given to the rule during the warning. How could this be possible ? Aren't policemen required to tell people their rights when they arrest them as we see in films ? What has happened after the film ? Note that I'm not american.