What is the meaning of landmark?

noun

• The position of a prominent or well-known object in a particular landscape.
  • usage: "the church steeple provided a convenient landmark"
• An event marking a unique or important historical change of course or one on which important developments depend.
  • usage: "the agreement was a watershed in the history of both nations"
  • synonyms: turning point, watershed
• A mark showing the boundary of a piece of land.
• An anatomical structure used as a point of origin in locating other anatomical structures (as in surgery) or as point from which measurements can be taken. .