DETROIT (WXYZ) - From the street, it has a striking, one-of-a-kind appearance.
It's the G.A.R. Building--Detroit's castle.
"It's a behemoth of a structure and it's very solid and it has remained solid through the years," said Tom Carleton, who is restoring the historic building over the years with his brother David, and their business partner Sean Emery.
"On some of the walk throughs, we realized what an amazing opportunity this building was," Tom added.
The building on Grand River served as a gathering place and social home for the men who kept the union together during the Civil War.
The Grand Assembly Hall was a place for meetings, dinners and concerts.
The tile floor in the building's front entrance remains intact and is being preserved in the restoration.
There are 130 windows. Much of the original glass has been saved along with the woodwork and wooden floors wherever possible.
"The doors have been rebuilt. Everything else is original," David told Detroit 2020.
The brother's media business, Mindfield, will occupy the fourth floor. They'll be looking for one or two tenants for two other floors. A diner and tavern will fill the street level.
"We're committed to make sure it's 120 percent of what people are expecting. It's a way to give back, a way to prove that Detroit's coming back," David said.