A mantrap (also called a security airlock or interlocking door system) consists of two doors that cannot be open at the same time. You enter the space between them, the first door closes, and the second door opens only after successful authentication. This design prevents tailgating, where an unauthorized person follows an authorized one through a door. Mantraps are common in data centers, high-security zones, and server room access points. In your physical security concept under ISO 27001 Annex A.7, a mantrap can be an effective control for areas that require the highest level of protection.