The Vatican chose to stage its pavilion inside Venice’s women’s prison, and through a deal with the Italian Justice Ministry, invited inmates to work alongside the artists. The result is a multimedia exhibit “With My Eyes,” that is open to the public by reservation only and under strict security conditions.

The Vatican exhibit has turned the convent-prison into one of the must-see attractions of this year’s Biennale, an unusual art world darling that greets visitors at the entrance with Maurizio Cattelan’s wall mural of two giant filthy feet. The work, titled “Father,” recalls Caravaggio’s dirty feet or the feet that Francis washes each year in a Holy Thursday ritual that he routinely performs on prisoners.

Greeting the prisoners, the Pope remarked: "Let us not forget that we all have mistakes to be forgiven for and wounds to heal, I too, and that we can all become healed who bring healing, forgiven who bring forgiveness, reborn who bring rebirth". The inmates donated to Bergoglio products that they make in the prison laboratories, including natural soaps and a new white skullcap, which the Pope immediately put on.

After that encounter, Francis heads by boat across the Giudecca Canal to Venice’s iconic Santa Maria della Salute basilica to meet with young people. Then he is driven by golf cart over a pontoon bridge laid across the Grand Canal for the occasion to Piazza San Marco, where he celebrates Mass in the shadow of the city’s spectacular Byzantine basilica.

Francis’ dizzying morning visit, which will end before lunchtime, represents an increasingly rare outing for the 87-year-old pontiff, who has been hobbled by health and mobility problems that have ruled out any foreign trips so far this year.

But it’s also unusual because it comes as Venice, sinking under rising sea levels and weighed down by the impact of over tourism, is in the opening days of an experiment to try to limit the sort of day trips that Francis is undertaking.