The Committees for the Defense of the Revolution were Fidel Castro's brainchild nearly 60 years ago, created to keep watch over a shaky regime -- now, they are an enduring symbol of communism in Cuba.
While their role may have changed somewhat, these bodies remain overseers of the revolution at a local level -- and will be charged with ensuring discipline when Raul Castro hands over the presidency to his successor on April 19.
In his modest home in Cienfuegos, located 230 kilometers (about 145 miles) from Havana, Orlando Fernandez remembers perfectly listening to a radio broadcast of Fidel's speech to the nation on the night of September 28, 1960.
Castro had been in power for a little over a year, but he had not yet revealed his socialist bent.
"We started to set off firecrackers, and at that moment, Fidel had this marvelous idea and said: 'We are going to create an organization to defend the revolution'," recalled the retired agricultural worker, 87.
The new revolutionary regime faced armed attacks, primarily in Havana, many of which were instigated or backed by Washington.
"We are going to create a collective revolutionary surveillance system. They are playing with the people, and they don't know the tremendous revolutionary force of the people," Castro told a large crowd of supporters gathered in the capital.
Fernandez, one of the first to join, was elected to the head of the CDR, as they are known in Spanish, in his neighborhood of Pueblo Nuevo in an inaugural vote.
"I am a founder of the CDR," the elderly man, now frail and with thinning hair, said with pride. He has been an active member for four decades.
Considered "the eyes and ears of the revolution," the CDR's logo shows a man brandishing a shield and a machete, accompanied by the slogan "on guard."
Every committee has a president, a surveillance chief, an organizer and an ideologue who keep detailed records on local members.
Castro opponents called them "chivatos" -- or "informers" -- and they kept an eye on anyone whose ideas or behavior seemed suspect.
Thousands of cells exist in every neighborhood, in every village in the country, with around eight million members -- more than three-quarters of the island's population.
Their national coordinator, Carlos Rafael Miranda, is one of 31 members of Cuba's Council of State, the country's executive body.
The defense committees are particularly visible during elections. They preside over neighborhood meetings, scrupulously controlling citizens' participation and interfering in candidate nominations.
This ideological gatekeeper system -- with cousins in Venezuela and Ecuador -- survived the economic and social upheavals that followed the end of the Cold War.
And step by step, the committees have taken on tasks like catching drug traffickers and combatting tax evasion. Others work to fight crime, with designated "watchmen" to keep an eye on late-night grocery stores.
Members also promote social benefits and coordinate services like vaccination campaigns and blood drives, as well as organizing volunteers for community projects like clearing litter or pruning trees.
They played a crucial role mobilizing volunteers as Hurricane Irma battered the island nation last year.
Noting a "change in context" since the Cold War ended, Cuban affairs analyst Arturo Lopez-Levy, who lectures at the University of Texas Rio Grande Valley, said today "the role of the CDR is more restrained, less important for new generations and of fundamental value to the community."
Fernandez says he hopes, though, that the groups will survive, saying they are inseparable from Cuban communism.
"The revolution is here to stay. No one is going to reverse it," he said.