Carrie Furnaces, Pennsylvania

Across the Monongahela River from the old Homestead Steel Plant site (now a shopping center) are the remains of the Carrie Furnaces, a preserved ruin of the steel industry. There used to be seven blast furnaces here, smelting iron for the mills at Homestead, which was transported by rail to the plant over a hot metal bridge. The first furnaces were built in 1884, and they went offline in 1978. Only two furnaces remain, numbers 6 and 7, with surrounding buildings. They are being preserved by the Rivers of Steel Heritage Corporation and are sometimes open for public tours and art events. Though other blast furnaces around the country are visible from public space, these (like the Sloss furnaces in Alabama) are some of the few where the public is allowed to wander inside.