Location:
Central Poland, urban environment.
Size:
Around 4 centimeters long.
Time:
Early July.
Images:
That is a moth, in the family Erebidae. It is in the genus Catocala. Wikipedia has a nice page on Lepidoptera of Poland. https://en.wikipedia.org/wiki/List_of_Lepidoptera_of_Poland including all the Catocala there.