"This fort is a lot bigger than it appears from outside," explains Robert McCormack, director of visitor experience at Fort Adams Trust, as he opens the gate to one of the largest, most complex forts on the East Coast.
"It certainly was used heavily during the Civil War," says McCormack. "They used this as a staging ground, a training ground. They gathered soldiers here before they would leave for war."
And that's how it was used through World War II.
"There were over 400 Irish laborers that helped to construct this fort," says McCormack, noting that 4 million bricks were used during construction, along with slate and shale.
The Fort Adams Trust is slowly restoring the relic; it had been abandoned, quiet for 60 years. The officers quarters in the east wall are run down, open to the elements, but show evidence of design details and craftsmanship.
Slanted stairs lead visitors to the top of the northeast bastion of the fort -- the top of a wall, featuring grasses that helped the behemoth blend into the landscape.
"I often joke this is the real reason the Army chose this spot. It is an unbelievable view," says McCormack, as he gazes out to the Newport Bridge.
The fort -- which now hosts summer music festivals -- never came under attack, though it was ready. And it still is: seven of the original 468 cannons still exist.
The tour highlight is dark though: visitors can walk down into the mysterious underground tunnels.
"Certainly there are people who say they remind them of the Catacombs," says McCormack. "Kids love the tunnels."
The daily, guided tours last one hour and involve about a mile of walking. Tickets cost $12 for adults and $6 for youths. Click here for more information.