The Louvre in Paris opened first. The Louvre, originally built as a fortress in the late 12th century, was converted into a public museum during the French Revolution and officially opened in 1793. The Prado Museum in Madrid was established later, opening to the public in 1819 as a royal museum to exhibit works of art owned by the Spanish monarchy. Therefore, the Louvre predates the Prado by about 26 years.