The story of the 19th century factory building hidden within modern Bronx high-rise towers

You can see it peeking out from the Harlem River Drive or through the chain-link fence of the Third Avenue Bridge: a five-story red brick building almost buried behind glass and steel apartment towers. The towers are newish luxury rental residences built on the Bronx side of the Harlem River. Shiny and modern, they bring Manhattan-style living spaces to a section of the borough that some canny real estate people have tried to rebrand as “SoBro.” But the red brick building, which is longer than it appears and has faded letters painted on its Manhattan-facing side, is a curiosity. It’s not just shielded by the apartment towers; it looks stuck, wedged between their outer walls. How did it avoid the wrecking ball when the apartment buildings were under development, and what is its backstory? Turns out this timeworn survivor played a role in two crucial businesses that practically defined the industrial South Bronx since the middle of the 19th century. First, the ironworks business.…