When word got out that Oakland’s beloved hot dog institution “The O” was closing, it took no time for The Odd, Mysterious & Fascinating History of Pittsburgh to chime in on Facebook. It was originally called “The House of Beef,” notes Odd Pittsburgh, showing an early photo of a worker carrying at least a dozen dogs on one arm, and another pretending to eat them.

The Original Hot Dog Shop in 1960.

If there’s odd, mysterious and/or fascinating history of Pittsburgh to be found anywhere, Odd Pittsburgh (as it’s also known) is on the case.

OddPittsburgh is many things: It’s a Facebook account (with 125,000 followers), a Twitter account (with 21,500 followers) and an Instagram account (with 22,000 followers). It’s a podcast, The Pittsburgh Oddcast, and a show on KDKA radio (Saturday nights at 7:30 p.m.). It’s all done, pretty much for fun, by John Schalcosky.

“Pure curiosity — that’s literally all it was,” says Schalcosky. “I went to film school and UCLA for music. Nothing to do with history. While I was in the film industry, living in Hollywood — it’s such a historic town — I kept looking at buildings and wondering what places used to be. I’d look it up, and find out, ‘Oh, this place used to be the Copacabana, which is boarded up, but is this cool thing that I remembered from old Bugs Bunny cartoons.’ How come no one knows it? It kind of bothered me. When I moved back to Pittsburgh, I started doing the same thing.”

It started with a strange story that Schalcosky read about the Allegheny River.

“Why don’t people know that the Allegheny River was named after an ancient race of giant people called the Allegewi that once inhabited Western Pennsylvania?” asks Schalcosky.

“The earliest origination of this naming of the river goes back to Zadok Cramer, and he had a navigational journal that he published here in Pittsburgh,” says Schalcosky. “He published them every year. The earliest you can find is 1802. Even then, it references earlier history. He’s talking almost like it’s no big deal.”

Cramer relates legends of the Lenni Lenape (or Delaware) people, who fought the giant Allegewi and pushed them out.

To get a little weirder, Schalcosky kept finding references to extremely tall people discovered in Western Pennsylvania archaeological digs.

“In 1921, the curator of the Carnegie Museum himself, William Jacob Holland, was out on an archaeological dig in Verona, and discovered 9-foot-tall people buried in a cave,” says Schalcosky. “There were two of them. It was such big news that it appears in the annual of the Carnegie Museum, it’s in all the newspapers, and they even put it on display.”

“Now, if you just Google 9-foot-tall people, you’ll find that none exist. It’s a legitimate weird story that has a Pittsburgh connection.”

Newspaper account from May 7, 1915.

“It’s not the only time it happened,” he adds. “In 1914, Westmoreland County, they came across 40 skeletons — two of which were of gigantic size. In the McKees Rocks burial mound, of the 38 skeletons they found there, one of which — they called ‘the Chief’ — was a guy who was like eight and a half feet tall.”

“How crazy is that?” asks Schalcosky. “That was the first story I was reading about. I thought that can’t be true, but it appears in every single history of Pittsburgh. And yet nobody told me that in school. I need to know more.”

What’s considered historic is, of course, subjective.

“When you talk about Pittsburgh history, most people think about Fort Duquesne or something,” says Schalcosky. “I’m talking about on this day, April 20, 1972, Pink Floyd played in Oakland at the Syria Mosque and played the entire ‘The Dark Side of the Moon’ album, just 35 days before they’d go to Abbey Road Studios to record the album. I think that’s historic.”

Along with fascinating stories, Schalcosky loves discovering old photos of historic Pittsburgh. A current project involves the first World Series between Boston and Pittsburgh in 1903. To find them, he had to look outside the usual places.

“If you look at the Historic Pittsburgh website, or search any Pittsburgh-based institution, you might find two or three photos,” says Schalcosky. “But if you look in the Boston Public Library, their archives, there are a hundred.”

Doing this doesn’t make him any money. He works in life insurance for a living.