What happens if the United States is under a nuclear attack? The president will be taken to a secure site near Colorado Springs, known as Cheyenne Mountain Complex. This place is built into 2,400 feet of solid granite.

What would happen if the United States faced a nuclear attack? One of the first things would be taking the president to safety. For this, the country has a dedicated place as per protocol. This place is the Cheyenne Mountain Complex near Colorado Springs.

It is a Cold War-era facility that can withstand a direct nuclear blast. The idea is to safeguard the head of the country to ensure the government continues to run in the face of a catastrophe. Right now, it acts as a fallback command centre for key defence operations. So, how strong is the Cheyenne Mountain Complex?

According to reports, the place carved into 2,400 feet of solid granite spans 5.1 acres. It houses 15 buildings and has everything that will allow it to function without any outside support in case of a nuclear attack. Its bomb blast doors have been built to resist explosions within 1.5 miles.

The complex has electricity and water, with an internal power plant in place, while water is sourced from underground lakes. Food is also not a problem with storage facilities available. Communications and networking systems are fully updated and support 24/7 operations.

But there is one more thing that is totally unexpected - A Subway restaurant, which is reportedly the “most secure Subway” in the world. It is fully functional and serves the current staff. Talking about the complex, Colonel Cory Kwasny of NORAD told The Denver Post that it feels like "you’re walking into a time capsule."

The protocol states that the president of the United States would first be moved to a bunker under the White House. From there, he would board an E-4B "Doomsday plane" to the Colorado facility.

The airplane is equipped with command and control systems to facilitate government functioning during national emergencies. Several senior officials would accompany him.

Some of them will go to the Cheyenne Mountain Complex with the president, while others, such as the Secretary of Defence, will be taken to Mount Weather or Raven Rock. This would ensure that someone is always in command, even in the worst scenario.