The Naval Historical Museum was located until 2013 on the fourth floor of the Palace, occupying a space of 1,346 m2. The collection included models, photographs, maps and other items from the different eras of navigation in Mexico. The museum is divided into six areas, labeled A through F each relating to a particular era or aspect of Mexico maritime history. Section A is dedicated to the origins of navigation both in the Old and New Worlds up to the first maps of the New World. Section B deals with maritime events of New Spain. Section C deals with the time period after Mexico gained her Independence in 1821 until the beginning of the 20th century. Section D covers the Mexican Revolution from 1910 to 1920, including the battle between the "Tampico" and the "Guerrero" as well as the United States occupation of Veracruz. Section E is entitled "Modern Mexico" and covers the decades between 1920 and 1970, which includes Mexico's part in World War II. The last section, F, is titled "Contemporary Mexico" from 1970 to 2004, which focuses on the Mexican Navy's latest acquisitions as well as future projects.