"I was expecting a freshen up of an older building. And boy was I surprised," Jason Acquisto, who attended the open house, told WISH-TV.
The renovation transformed the interior of the arena that once hosted the Beatles and the NBA's Indiana Pacers. The main concourse offers natural lighting and a second-floor concessions area allows customers to see inside the arena. Amenities now include a spacious lobby with elevators to carry guests up to the main concourse and a double-tiered seating bowl.
The fair said in a news release that it has preserved the building's history by reinstalling 96 original seats, recreating its original terrazzo floor, and leaving original walls and steel support beams exposed.
"I was so impressed by the grandeur," visitor Val Wolf told WISH. "The size. The way they opened it up. It is just beautiful."
The renovations also added more than 70 wall-mounted flat-screen TV monitors, a state-of-the-art sound system and a curtain system that allows for natural or artificial lighting.
The Coliseum with host minor league hockey's Indy Fuel and the IUPUI men's basketball team. It will have about 6,200 seats for hockey games and about 6,500 seats for basketball games.
Star Fair spokesman Andy Klotz says it's still working with the Indy Fuel to find a partner to buy naming rights to the building.
A formal ceremony reopening the Coliseum was held earlier in the day.
"The renovation is simply amazing - better than we ever imagined," Fairgrounds Executive Director Cindy Hoye said in a statement. "This is one of the most iconic structures in all of Indiana and we hope visitors appreciate the mix of past and present that went into the design."
The performers appearing in the Coliseum during this year's fair will include Robin Thicke, Pitbull, Hunter Hayes, the American Idol Live! 2014 Tour and comic Jim Gaffigan, who grew up in northwestern Indiana, the fair announced Thursday.
The renovations were paid for with $10 million from funds raised through the Indiana State Fair Foundation and $53 million from state-issued bonds that the state fair will pay back with revenues over about 20 years.