The U.S. Army may seem like an unlikely patron of the humanities, but over the last century the service branch has accumulated an unrivaled treasure trove of captured and commissioned war art. The collection of 16,000 paintings, photos, and sculptures is currently sitting in a football field-sized warehouse at Fort Belvoir, awaiting completion of a public Army Museum sometime around 2019.

The Army’s conservation warehouse includes works by Norman Rockwell, ordinary soldiers, enemy combatants, and even Adolf Hitler’s watercolors. The collection program began during World War I when the Army dispatched eight “combat artists” to roam the battlefield and record firsthand the experience of the average soldier.

During World War II they added captured Nazi and Fascist propaganda, confiscated from enemy capitals and deemed too controversial for public display. Thousands of these pieces were returned to Europe after the war, but the Army kept anything picturing a swastika or Nazi leader. World War II also brought in historic pieces, unrelated to war art, that were stolen from victims of the Holocaust and reclaimed by the Monuments Men.

The U.S. government’s attic counts a slew of collections like this across the country, under Park Service, Smithsonian, Archives, and Library of Congress stewardship. They’re generally overly bureaucratic affairs, tightly sealed to the public eye in an unfortunate compromise between preservation and security. The Army’s warehouse is a surprising exception to the norm, and they regularly allow journalists and researchers to come take a look. And when fundraising and construction of the Army Museum are complete in a few years the collection will be a national treasure accessible to anyone.