Think of it as a fortress of evidence so strong that no one can break through it.
Here are some synonyms for irrefutable:
* Unquestionable
* Indisputable
* Incontrovertible
* Unassailable
* Definitive
Examples:
* "The scientist presented irrefutable evidence of climate change."
* "The witness gave an irrefutable account of the crime."
* "The judge ruled that the defendant's alibi was irrefutable."