noun
seaward side; side facing the sea
Refers to the side of something (a building, road, train seat, etc.) that is closer to or faces the sea. Often contrasted with 山側 (mountain side).
このホテルの海側の部屋は眺めがいい。
The seaward-side rooms in this hotel have a good view.
電車で海側の席に座ると、海岸線が見える。
If you sit on the seaward side of the train, you can see the coastline.