Access control vestibules, also known as mantraps or airlocks, are physical security features that require individuals to pass through two or more doors to enter a secure area. They are effective at preventing tailgating, as only one person can pass through each door at a time.
Reference:
https://www.comptia.org/content/guides/what-is-a-mantrap
CompTIA Security+ Study Guide, Sixth Edition (SY0-601), page 222