The Navy announced Tuesday that it plans to build a new $450 million flagship museum, replacing the out-of-date facility that has been at the Washington Navy Yard for more than 50 years.

The new facility would replace the existing National Museum of the U.S. Navy, which has been in Building 76, a cavernous, old former gun factory at the Navy Yard.

But because it is on an active installation with tight security, public access has been difficult.

It is currently closed because of the coronavirus pandemic.

“The ideal site for the new . . . museum is in the vicinity of the . . . Washington Navy Yard, but the final location is not yet finalized,” the Navy said in a statement. The new site “will give the public unfettered access to U.S. Navy history and heritage.”

But the Navy said it is still working to acquire the necessary six acres of land outside the Navy Yard. “There are significant multiparty negotiations, environmental studies and legislative actions” that must take place before a deal is finalized, the service said.

“The negotiations are at kind of a sensitive stage,” said retired Rear Adm. Samuel Cox, director of the Naval History and Heritage Command at the Navy Yard. “That’s where we want it to go.”

The Navy is also seeking a nonprofit fundraising partner to help raise the money.

The Heritage Command will coordinate the building of the new museum, which could be finished by 2025.

Once completed, the Navy’s museum will join the new National Museum of the U.S. Army, in Fort Belvoir, Va., which just announced that it will open on Veterans Day, and the National Museum of the Marine Corps, in Triangle, Va., which opened in 2006.

In making its announcement, the Navy displayed renderings of a sleek new building that appeared to be on or adjacent to the historic yard on M Street SE. The museum will be “an advanced, campus design,” the Navy said.

The renderings show a design with a central, light-filled atrium.

“It’s awesome,” Cox said at the Navy Yard on Tuesday.

“We’re not the ministry of propaganda,” he said. “My job is to tell accurate history about the United States Navy. Much of it is glorious. But there’s also tragedy, defeats, buffoonery. It’s all there.”

“But on balance, I think the taxpayers of the United States have gotten their money out of the United States Navy,” he said. The current museum, which has a collection that dates to 1800, opened to the public in 1963.

The yard itself dates to 1799. The first artifact collected was a French gun captured during the Quasi-War with France, from 1798-1801.

The museum also has a gun used by Spanish conquistador Hernán Cortés and an array of exquisite old ship models, as well as the deep-sea submersible Trieste.

It also has a large Navy Corsair fighter suspended from the ceiling and a dented bell from the USS Merrimack — renamed the CSS Virginia by the Confederates — famous for its 1862 duel with the Monitor.

And it has an enlarged photo of the attack on Pearl Harbor taken from a Japanese plane.