This is the 2182nd most frequent French word.
côtières
"Coastal" or "related to the coast."
In this sentence, 'côtières' is an adjective describing 'regions', indicating areas adjacent to the coast.
Les régions côtières sont souvent très touristiques.
Coastal regions are often very touristy.
Here, 'côtières' modifies 'plages', specifying that the beaches are located near the coastline.
Les plages côtières attirent de nombreux visiteurs chaque été.
Coastal beaches attract many visitors every summer.
The word 'côtières' describes 'villes', emphasizing their proximity to the coast.