WASHINGTON — Two of the United States’ intelligence agencies have completely renovated their museums of spycraft, displaying dramatic stories of notable U.S. spies and informants, as well as paraphernalia from intelligence work. But one of the museums will remain off limits to the public.

In time for its 75th anniversary this year, the Central Intelligence Agency has overhauled and refurbished its museum of secrets. It features spy gadgets both successful (a Tabasco sauce-covered dead rat in which to hide messages) and not (a pigeon-mounted camera and a mini spy drone designed to look like a dragonfly). It has fascinating, beautifully arranged artifacts from significant espionage operations.

However, the C.I.A. Museum is on the agency’s heavily protected campus in Langley, Va., a location that is not open to members of the public — unless they find themselves summoned to its headquarters. The C.I.A. opened the renovated museum to family of personnel one weekend and to members of the news media Saturday.

Many of the artifacts are celebrations of the agency’s triumphs. The museum has a model of Osama bin Laden’s compound and a brick taken from the site. There is art made by the great comic book artist Jack Kirby, used by the C.I.A. as props for a fake movie production company in an operation to rescue diplomats in Iran (depicted in the 2012 movie “Argo”). And there are disguises worn by people while working to salvage the wreck of a Soviet submarine carrying nuclear missiles from the ocean’s floor.

There is a reconstruction of the tunnel under East Berlin that allowed the United States to tap into Soviet communications for roughly 18 months.

One of the newest additions to the collection of artifacts is a model of the building in Kabul where Ayman al-Zawahri, the Qaeda leader, was hiding when he was killed by a U.S. drone strike in July. The C.I.A. placed the model in a wooden box when it was brought to President Biden to discuss the operation, and the bottom of the box can be seen in the C.I.A. display case.

Perhaps in part because it is restricted from the general public, the C.I.A. Museum does not shy from the agency’s failures: operatives caught by governments, moles who give away informants, the groupthink of the Iraq war, the Bay of Pigs.

“A big part of this museum is for our officers, and for them to know the lessons of the past,” said Robert Byer, the director of the C.I.A. Museum. “For that reason, we cannot just be sugarcoating our history or touting our successes. We really have to make sure this is a full history of the C.I.A. so they can understand their history and do a better job because of it.”

Among the museum’s carefully crafted exhibits is the story of Martha Peterson, the first female case officer sent to work in Moscow. Her assignment was to collect and pass information to an operative who was a Soviet diplomat, to whom she would also provide a suicide pill to use if he was captured. The diplomat ultimately was seized and died by suicide, leading to Ms. Peterson’s arrest while she was placing a message in a dead drop.

While the C.I.A. gathers intelligence, conducts analysis and executes covert operations, the National Security Agency focuses on collecting electronic communications and making and breaking codes. That is the focus of its reimagined showcase at the National Cryptologic Museum in Annapolis Junction, Md.

The museum of the N.S.A., sometimes called “No Such Agency” in a nod to its secretive practices, was designed to be accessible to the public, a contrast with the C.I.A. Museum.

“It’s a wonderful paradox that ‘No Such Agency’ has the only museum in the U.S. intelligence community that’s completely open to the public,” said Vince Houghton, the museum director.

The cryptological museum closed in 2020 amid the Covid pandemic and Dr. Houghton, a former historian and curator at Washington’s popular International Spy Museum, used the time to renovate the building and meticulously search the National Security Agency’s archives of equipment.

“There are things that people didn’t know existed, and there are things that people had thought had been lost for decades,” Dr. Houghton said.

In the museum, which reopens Oct. 8, Dr. Houghton emphasizes unique artifacts amid exhibits filled with strangely fascinating code-making and code-breaking machines. Its collection extends from the United States’ earliest days to the present. From World War II, there is the machine that broke Japan’s diplomatic encryption, and another that broke the German naval codes. There is also an Enigma machine used by Adolf Hitler, displayed behind glass; there are other ones that visitors can touch and use.

Dr. Houghton said almost all the artifacts he displays meet one of three criteria: They are the only remaining object of their kind; they are the first of something; or they were used by a specific person.

“I call it the holy trinity of artifacts,” he said.

The museum sticks to its mission of explaining cryptology to a broad section of the public. It acknowledges some losses: There is a memorial wall and displays that tell the stories of cryptologists killed in combat. But for the most part, the focus is on the machines and the code breakers who ran them.

There’s not much on the turncoats, however. One exhibit shows the tools that John Walker, a Navy warrant officer and Soviet spy, used to try and steal American codes for the Russians. But there is no mention of Edward Snowden, the N.S.A. contractor who revealed many of the agency’s secrets and then fled to Russia. (Because the Snowden case is an ongoing Justice Department investigation, the museum is limited in what it can say.)

The C.I.A. Museum, on the other hand, has multiple examples of spy games ending in failure or tragedy. It highlights the stories of C.I.A. officers wrongly accused of being spies and lays out the damage done by Soviet moles.

Among the collaborators whose work is celebrated is Adolf Tolkachev, an aviation electronics engineer. He reached out multiple times to the C.I.A. to offer his help, angered at the persecution of his wife’s parents under Joseph Stalin. In 1978, he got though to the Americans and used miniature cameras to pass on images of Russian secrets.

The value of Mr. Tolkachev’s intelligence, which vastly expanded American knowledge of Soviet missiles and fighter planes, earned him the moniker “the billion dollar spy.” While he was good at getting documents, he was not good at taking pictures. The museum includes a camera the C.I.A. built for Mr. Tolkachev, with a fixed focal length to ensure his pictures would be less blurry.

But his story also ends badly. Aldrich Ames and Edward Lee Howard, C.I.A. officers working for the Russians, gave up Mr. Tolkachev’s identity. He was arrested in June 1985 and executed in 1986.

“I feel I have a responsibility: It cannot be a rah-rah version of history,” Mr. Byer said. “Museums need to tell the truth.”