THE FORMER PITTSBURGH STOCK EXCHANGE BUILDING ALONG FOURTH AVENUE | COURTESY GOFOURTH PITTSBURGH

Tours of the historical “Wall Street of Pittsburgh” are getting a modern twist.

Mark Houser, a Pittsburgh Magazine correspondent and local historian who has written articles and books about Downtown’s skyscrapers and famous streets, will be leading smartphone tours on Saturday, Oct. 11, of Fourth Avenue — the city’s former financial district that was once known as the “Wall Street of Pittsburgh.”

His project, gofourthpittsburgh.org, will launch a new smartphone tour on that day, which actually will be free for anyone to explore. As part of the launch, he will be leading three, one-hour tours for a nominal fee, whose proceeds will go to charity.

The tours (starting at 11 a.m., 12:30 and 2 p.m.) will discuss about two dozen buildings from Smithfield Street to PPG Place — all with fascinating stories behind them. Several of the ornate buildings that once drew the city’s top financiers have been converted into residences, hotels and updated office space.

“These buildings are personal statements of ambition,” he says. “These are not just stories about boring bankers. They were big, swinging industrials that created the Pittsburgh that we know today.”

The skyscrapers that were built between 1892 and 1905 dramatically changed the city, he says. At one time, Fourth Avenue boasted more of the new steel-framed structures than any other section of the city.

Joining Houser on the tours will be Megan Harris, host of City Cast Pittsburgh. In addition, Dollar Bank — known for its distinctive Fourth Avenue entrance flanked by stone lions — will host a rare open house where docents will share the building’s history and architecture.

ORIGINAL DRONE-SCAN COMPOSITES OF BUILDINGS ALONG FOURTH AVENUE, WHICH WERE CREATED BY DIGITAL ARTIST CHRIS HYTHA. | COURTESY GOFOURTH PITTSBURGH

The smartphone tour will include skyscraper drone portraits of the buildings created by Philadelphia-based digital artist Chris Hytha, which would give tour-goers a chance to see the tops of these buildings.

“This project, gofourthpittsburgh, is to help people appreciate the fantastic architecture along the the Wall Street of Pittsburgh,” Houser says. “Chris is an expert of making these buildings accessible and to show what you can’t see from the sidewalk.”

Saturday’s tours also will include a visit to the Benedum-Trees Building art gallery, where there are large canvases of every skyscraper image on display.

Participants should meet in the gated park next to the Dollar Bank at Smithfield Street and Fourth Avenue. The tours cost $10, and proceeds will support Mission of Mercy Pittsburgh, the free dental, vision and hearing clinic coming up on Oct. 24-25 at the David L. Lawrence Convention Center.

Sign up for the tours here.