a recess in a coastline的用法和样例：
- A recess in a wall, as for holding a statue or an urn.
- A recess, as in a border or coastline.
- In a recess in the rocky cliffs behind the cataract is a cave. Lying hidden by the sheets of water cascading down, it is known as the Water Curtain Cave.
- He made a recession in the wall using a knife.