This is perhaps the most impressive of all the Carnegie Libraries here in Pittsburgh, although the one in Carnegie itself is equally as large, the Homestead library is has a huge theatre. The theatre seats over a thousand people for concerts, plays, and lectures. The theatre is said to be haunted and this library was recently featured on Ghost Hunters.
The Library is still in use and features a gym and locker rooms. This Library is said to be a gift or bribe to the people of Homestead after the great strike that resulted in a battle with Pinkerton guards in Homestead. Some steelworkers as well as Pinkerton Guards were killed in the battle. It's also said Andrew Carnegie himself haunts one of the rooms of the Library, knocking books off shelves.
This is another one of those hidden gems that people in Pittsburgh don't even know exist. I didn't know it existed until I saw Asia here.