Dramatic footage has emerged from inside El Salvador's mega-prison for gang members showing its concrete confinement cell and impenetrable security. The Centre for the Confinement of Terrorism (CECOT) in Tecoluca is home to 40,000 of the world's most dangerous men who will never be released - each one with at least one homicide conviction. And now YouTuber Nick Shirley has offered one of the most in-depth looks at the prison's interior yet. He also takes a tour of the solitary confinement chamber, a narrow cell comprising only a raised concrete platform used as a bed alongside a rudimentary toilet basin....