This is the 13789th most frequent Turkish word.
kıyısındaki
"Next to the shore of" or "by the edge of."
Here, 'kıyısındaki' describes the location of the flowers as being next to the river, stressing proximity or adjacency.
Gelirken nehır kıyısındaki çiçeklere dikkat et.
Notice the flowers by the riverside on your way back.
In this sentence, 'kıyısındaki' is used to connect 'parkin' (the park) with 'oturma alanı' (the seating area), indicating the seating area is at the edge of the park.
Parkın kıyısındaki oturma alanı çok sessizdi.
The seating area by the edge of the park was very quiet.
The word 'kıyısındaki' in this context is used as an adjective to describe the house's location near the seaside. It links 'deniz kıyısı' (seaside) and 'ev' (house) indicating proximity.