National Geographic Investigates - Peru's Mass Grave: The Ghosts of Kuélap

Journey into the extraordinary world of "The Witcher" — from casting the roles to Jaskier's catchy song — in this behind-the-scenes look at the series.

New exclusive access and never before heard testimony gives a unique insight into the mind of America's most notorious serial killer, Ted Bundy. Breathtaking archive from the time and the voice of Bundy himself, reveals the monster inside the man.

Unravel the case of Utah therapist Jodi Hildebrandt, whose child abuse arrest with parenting YouTuber Ruby Franke exposed a twisted tale of manipulation.

Ten of Muhammad Ali's former rivals pay tribute to the three-time world heavyweight champion.

Legendary journalist Gay Talese unmasks a motel owner who spied on his guests for decades. But his bombshell story soon becomes a scandal of its own.

A teen slams her car into a building, killing her boyfriend and his friend. What seems like a tragic accident becomes a murder case.

When Allied forces liberated the Nazi concentration camps in 1944-45, their terrible discoveries were recorded by army and newsreel cameramen, revealing for the first time the full horror of what had happened. Making use of British, Soviet and American footage, the Ministry of Information’s Sidney Bernstein (later founder of Granada Television) aimed to create a documentary that would provide lasting, undeniable evidence of the Nazis’ unspeakable crimes. He commissioned a wealth of British talent, including editor Stewart McAllister, writer and future cabinet minister Richard Crossman – and, as treatment advisor, his friend Alfred Hitchcock. Yet, despite initial support from the British and US Governments, the film was shelved, and only now, 70 years on, has it been restored and completed by Imperial War Museums under its original title "German Concentration Camps Factual Survey".

Serving life in prison for murdering their parents, Lyle and Erik Menendez speak out in this documentary explaining the shocking crime and ensuing trials.

Serial killer Dennis Nilsen narrates his life and horrific crimes via a series of chilling audiotapes recorded from his jail cell.

Louis Theroux travels to California to meet the man dubbed "the most dangerous racist in America"; Tom Metzger. Louis meets him, his family and his publicity manager as well as following him to skinhead rallies and on a visit to Mexico.