Before revision: Examples are: Cheyenne Mountain Complex Chiashan Air Force Base Iranian underground missile bases Raven Rock Mountain Complex Zeljava Air Base There are more than 10,000 underground military facilities worldwide.
After revision: Examples may be: Cheyenne Mountain Complex Chiashan Air Force Base Iranian underground missile bases Raven Rock Mountain Complex Zeljava Air Base There are more than 10,000 underground military facilities worldwide.