Which structural barrier is commonly used for security, such as chainlink fences?

Fences are frequently used as physical security barriers to protect property and delineate boundaries. Chain-link fences, in particular, are popular due to their durability, visibility, and effectiveness in preventing unauthorized access. They serve to create a clear periphery around a secured area while enabling visibility, which can deter potential intruders.

In terms of structural barriers, walls tend to be more solid and less transparent compared to fences, which can limit visibility. Access control refers more to systems or processes, such as locks or electronic systems, rather than physical structures. Shields are generally associated with protective measures against various types of hazards and are not commonly discussed in the context of security barriers like fences. Therefore, fences are the most appropriate choice for this question regarding structural barriers used in security settings.