This is the 3346th most frequent Polish word.
wakacyjnych
"Relating to holidays/vacations."
The word "wakacyjnych" here is an adjective in the genitive plural form, describing the months that are associated with summer (holidays).
Podróżujemy w czasie wakacyjnych miesięcy.
We travel during the summer months.
In this sentence, "wakacyjnych" is used as an adjective in the genitive plural form, describing the type of memories linked to holidays.
Planowałem wyjazd z moich wakacyjnych wspomnień.
I planned a trip based on my vacation memories.
Here, "wakacyjnych" describes "atrakcje" (attractions), indicating that the attractions are related to summer vacations.