The mafia's secret bunkers
30 April 2013 Last updated at 17:58 BST
Mafia historian John Dickie joins an elite Italian special forces unit, the Cacciatori or Hunters, as they discover a series of underground tunnels built by the mafia.
This sophisticated labyrinthine network is hidden under villages in Italy's southern region of Calabria and allows criminals to escape at a moment's notice.
Fully furnished bunker rooms and even apartments are built under ordinary family homes, enabling fugitives to spend months in safe hiding, protected by their communities through the mafia code of silence.
This World: The Mafia's Secret Bunkers is on BBC Two on Wednesday 1 May at 21:00 BST.