What constitutes a natural barrier?

A natural barrier is defined as a physical obstacle that occurs in nature and functions to deter or restrict access to a particular area. These barriers can include geographic features such as mountains, rivers, or dense forests, which are inherently effective in limiting movement and providing a protective boundary. Choosing the option that describes a natural object reflects an understanding of what constitutes a natural barrier versus an artificial one.

Artificial obstacles, like a fence or a locked gate, are man-made structures designed to control access to an area but do not fall under the category of natural barriers. Similarly, a security guard is a human presence employed for protection, which also does not align with the definition of a natural barrier. Focusing on the characteristics of what constitutes a natural barrier provides insight into how environmental features function in terms of access control.