The Inquisition arrived in Carcassonne in the early 13th century to finish what a crusade had started. The Cathars, a religious movement that had flourished across this region of southern France, had survived the military assault. Stamping out the last traces of their beliefs fell to Dominican friars, operating from four centres across the Languedoc, one of which was here.

The House of the Inquisition, marked by a discreet plaque reading Logis de l'Inquisition MCCCXXXIII, was where interrogators refined their methods over generations. Once the Cathars were gone, their scope expanded to encompass Jews, witches, lepers, Muslims and anyone who strayed from Catholic doctrine. The Spanish Inquisition, created a quarter of a millennium later, copied its practices directly from here.

VoiceMap's self-guided audio tour reads from an extraordinary open letter written by Carcassonne's own Consuls in 1285, publicly shaming a Dominican Inquisitor when every other appeal, including one to the Pope, had failed.