The Guardian has a fascinating article about the Vatican's secret real estate empire.
How the Vatican built a secret property empire using Mussolini's millions
Papacy used offshore tax havens to create £500m international portfolio, featuring real estate in UK, France and Switzerland
Few passing London tourists would ever guess that the premises of Bulgari, the upmarket jewellers in New Bond Street, had anything to do with the pope. [...]
But these office blocks in one of London's most expensive districts are part of a surprising secret commercial property empire owned by the Vatican.
Behind a disguised offshore company structure, the church's international portfolio has been built up over the years, using cash originally handed over by Mussolini in return for papal recognition of the Italian fascist regime in 1929.
The Mussolini money was dramatically important to the Vatican's finances. John Pollard, a Cambridge historian, says in Money and the Rise of the Modern Papacy: "The papacy was now financially secure. It would never be poor again."