Canterbury Cathedral has been making pilgrims behave strangely for over 800 years.

It was here, on 29 December 1170, that four knights hacked Archbishop Thomas Becket to death — with one final sword blow so violent it sliced off the top of his skull. Henry II, riven with guilt, walked barefoot to the cathedral in a hair shirt to be flogged by forty monks. Miracles followed so quickly that Becket apparently outperformed the Virgin Mary in the rankings.

The cathedral that draws visitors today is itself a palimpsest of strange histories: an Archbishop buried without his head (replaced, sensibly, with a cannonball), Becket's bones that may or may not have been fired from a cannon, medieval stained glass that survived the Puritans only because an angry mob shook a vandal off his ladder.

VoiceMap's self-guided audio tours trace this full arc: from the murder itself at the Martyrdom, through the Trinity Chapel where Becket's jewelled shrine once stood, to the crypt's unsolved mystery of whose bones lie beneath the floor.