This is the 15602nd most frequent Polish word.
strzeżonych
"Strzeżonych" means "guarded" or "protected" in English.
The word "strzeżonych" functions as an adjective in the genitive plural form, describing "parkingów" (parking lots), indicating that they are guarded.
Zawsze staraj się korzystać ze strzeżonych parkingów.
Always try to use guarded parking lots.
Here "strzeżonych" modifies "tajemnice" (secrets) in the accusative plural form, emphasizing the level of guarding or secrecy associated with the secrets.
To są najbardziej strzeżonych tajemnice w historii.
These are the most guarded secrets in history.
The term "strzeżonych" acts as an adjective describing "pomieszczeniach" (rooms), and it is in the locative plural form, indicating that the rooms are guarded.