It’s billed as the “grandparent of the modern skyscraper,” though it’s unlikely you’ve heard of it. From the outside, Shrewsbury Flaxmill Maltings resembles any number of red brick relics from the industrial revolution that litter the English north and Midlands.

But as the first building in the world to be built from a precast iron frame, this 18th-century mill is, according to its custodian, a “profoundly important” monument of world architecture — the forerunner of all iron- and steel-framed buildings, from 20th-century icons like the Empire State Building to 21st-century behemoths like the Burj Khalifa in Dubai.

Completed in 1797, Shrewsbury was the first building in the world to be built from a precast iron frame. This is the earliest known rendering of the site. Shropshire Archives

Now, this slab of English industrial heritage is ready for its close-up. This spring, English Heritage, the charity that manages Britain’s state-owned historic monuments, took ownership of the Shrewsbury site with a mission to highlight its past and future.

The factory may be a miracle of modern engineering, but its legacy is stained by the suffering of the workers, many of them children, who toiled there in harsh conditions. It now houses a museum dedicated to that history, but it is also being reborn as upscale offices for entrepreneurs. Soon, parts of the wider site will be converted into smart new housing.

The transformation is the latest in a push to find new uses for outsized relics of Britain’s industrial past, driven in part by heritage campaigners. “Heritage is often castles, thatched cottages, stately homes,” said Matt Thompson, English Heritage’s curatorial director. “Industrial heritage was for a long time overlooked because it’s not immediately responding to what we consider significant.”