Our feature OKI Wanna Know is your chance to ask that nagging question that seems to have no answer. This week, we look at an important part of Cincinnati's skyline with WVXU's Bill Rinehart.
Todd Osborne of Loveland has been wondering about the top of one of Downtown's landmarks.
"What exactly is on top of the PNC tower? The little structure on top of the entire building — what exactly is that?" Osborne asks. "I used to work at Channel 48, and I would videotape from Carew Tower and from across the river, and would always use that as a focal point to zoom in and out of. What is it?"
Greg Hand, who runs the Cincinnati Curiosities blog, says the name of the building in question depends on who you ask.
"The 4th and Vine Tower, previously the Central Trust Tower, or the PNC Bank Tower, or the Union Central Tower — you can pretty much date Cincinnatians by what they call that building."
Hand says it started in 1913 as the Union Central Tower, and it wasn't the city's first high rise. That honor belongs to the Ingalls Building, which is now a Courtyard by Marriott, right across the street and erected 10 years before the 4th and Vine Tower.
"The Ingalls Building was so revolutionary when it was constructed that one of the newspapers assigned a reporter overnight to watch it because they were convinced it was going to fall down."
Hand says the 4th and Vine Tower was the one that put Cincinnati on the map as a major metropolitan city. He says the owner went to New York to find an architect by the name of Cass Gilbert.

"Cass was a very accomplished architect. One of his major commissions was the United States Supreme Court building," Hand says. "He was brought up in the firm of McKim, Mead and White, an extremely influential New York City firm that trained its architects in classical structures."
Hand says those classical structures include St. Mark's Campanile in Venice, which he says shares some traits with the 4th and Vine Tower.
"It's structured very much like a classical column, with a base and a shaft and a capital. The Campanile in Venice actually has this little structure at the top. Then it goes to a pyramid, and then a bronze statue sitting on top of it."
Hand says the Greek columns near the top of the 4th and Vine Tower are inspired by one of the seven wonders of the ancient world: "The tomb of King Mausolus in Halicarnassus in Western Turkey. That building was so well known King Mausolus' name continues today in the term 'mausoleum.' "
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You can find similar elements in the Civil Courts Building in St. Louis, the War Memorial in Indianapolis, and the Masonic House of the Temple in Washington, D.C.
Hand says the 4th and Vine Tower may have been drawing from the past, but it included at least one forward-looking element: a guidance light for aircraft.
"That beacon was visible for miles around, at night especially," he says. "This was a time when they weren't entirely sure where airplanes were going to go. There was even some thought that tall buildings would include mooring stations, or landing stations for aircraft."
Of course, that never happened.

Hand says Cincinnati's building was originally the home of an insurance company.
"The Union Central Life Company was started in the 1860s by the Methodist Church," he says. "So, in addition to this very Grecian, very classical sort of structure, if you look down toward the base, there's a lot of Christian iconography that's built in. You will find representations of pelicans."
Pelicans were a common Christian symbol during the Middle Ages.
That's all interesting and good to know, but it doesn't answer the question: What is on the very top of 4th and Vine, sitting at the pinnacle of the pyramid roof?
It's square-ish bronze temple-like structure. If you look closely, you'll see it too, has columns. And if you ever looked down on it — say, when the Carew Tower observation deck was open — you may have seen a big round hole in the middle of those columns.

Despite some rumors, there never was a spire jutting up out of that hole, and Hand says it was not for broadcasting equipment.
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"Really the first kind of commercial radio stations around Cincinnati would have been a decade later, into the 1920s," he says. "So it wasn't built to include a radio tower."
So, what is it?
"It's a decorative cover for a very large smokestack," Hand says. "This was a building built in 1913, so you're going to be heating the building, you're going to be heating the water with coal. So you're going to have a very large coal furnace in the lower levels of this building, and the smokestack just goes up through the center of the building, and out through that temple."