This is the 17310th most frequent Polish word.
zamkniętych
"Closed."
Here, 'zamkniętych' refers to 'corridors' (korytarzy), emphasizing that they are enclosed or bounded within a structure.
W ciągu zamkniętych korytarzy słychać było kroki.
Footsteps could be heard in the enclosed corridors.
In this case, 'zamkniętych' qualifies 'containers' (containerów), specifying that the containers were securely sealed or not open.
Podczas spotkania używano zamkniętych containerów na dokumenty.
Closed containers were used for documents during the meeting.
The word 'zamkniętych' describes the state of the 'facilities' (obiektów), indicating that they are closed or inaccessible.