If you don’t know about it and aren’t looking for it, chances are you won’t even notice it. And if you do notice it, you might not realize that the building at the corner of Forbes Avenue and Wood Street is its own, remarkably narrow structure.

Now the Skinny Building, a Downtown structure as mysterious as it is narrow, is getting some much-needed love from the Pittsburgh History & Landmarks Foundation.

At 5 feet, 2 inches wide and 80 feet long, the three-story building that might be the world’s thinnest has served a variety of purposes over the years. Since around 2001, the two dozen large windows on the second and third floors have been used to display public art.

“It’s been a number of things,” says Jeremy Waldrup, President and CEO of the Pittsburgh Downtown Partnership. “It’s been a produce stand, a lunch counter, a hair salon — but I’m not sure why it is the way it is.”

Now, the Urban Redevelopment Authority, which purchased the building in March along with the next-door Roberts Building, has enlisted PHLF to restore the building facades, which will include fixing its tile roof, wooden columns and tin ceilings. The open-air first floor, which is currently occupied by a t-shirt vendor, will remain a functional part of the building.

The PHLF also plans on reincarnating the Roberts Building’s original marquee and touching up its trim.

Landmarks Design Associates will design the improvements and Waller Corporation will build them. The improvements will cost about $550,000 and will be funded with part of a $4 million state grant.

The six-foot-wide strip of land the Skinny Building occupies is most likely a remnant from 1903, when the city widened a street called Diamond Way to create what is now Forbes Avenue. Andrew Mellon owned the parcel of land for a time, but the Skinny Building’s architect and intended purpose remain a mystery.