The Washington University Hilltop Campus Historic District was the site of the 1904 Louisiana Purchase Exposition and the 1904 Summer Olympics. Many of the exposition buildings were temporary in nature, but a number of permanent structures were built and are used by Washington University, which calls this area the Danforth Campus. The district includes more than fifty structures, of which twenty are in the Collegiate Gothic style. University buildings included: Other buildings constructed for the Exposition include: