At the Harold Washington Library Center visitors will find 756,000 square feet and 10 different levels. The Harold Washington Library Center was built in 1987. Its impressive collection of books is housed in a building of old-world architecture. A rooftop winter garden provides a nice retreat from the 13 million works housed below, while hosting the periodic special exhibition. The Guinness Book of Records acknowledges the library as being the largest public library building in the world.