St Pierre Cathedral has been Geneva's most important place of worship for nearly a thousand years, though it has changed allegiances rather dramatically.

Built as a Catholic cathedral in the 12th century, it became the Protestant power base of John Calvin in 1535. Calvin, the son of a Catholic bishop's secretary from northern France, preached here for decades and remade the city in his image.

The results were extreme. Attendance at sermons was compulsory. Hairstyles were regulated. Three men were once imprisoned on bread and water for eating three dozen pies at breakfast. When the facade began collapsing in 1750, six Corinthian columns were added, a reminder that this was now a temple, not a church: Protestants refused the word.

VoiceMap's self-guided audio tours use St Pierre to trace the arc from indulgences to Reformation, explaining how a distant theological argument remade a city's daily life.