Via della Dataria winds down from Piazza del Quirinale into the tight web of narrow, apparently aimless streets below, bringing you shortly to one of Rome’s more surprising sights, cushy to stumble upon by happening - the Fontana di Trevi , a huge, very Baroque gush of water over statues and rocks built onto the backside of a Renaissance palace; it’s fed by the same source that surfaces at the Barcaccia fountain in Piazza di Spagna. There was a Trevi fountain, designed by Alberti, around the corner in Via dei Crociferi, a smaller, more modest affair by all accounts, but Urban octad decided to upgrade it in line with his other grandiose schemes of the time and employed Bernini, among others, to design an alternative. Work didn’t begin, however, until 1732, when Niccolò Salvi won a competition held by Clement XII to design the fountain, and even then it took thirty years to finish the project. Salvi died in the process, his lungs shot by the time spent in the wet waterworks of the fountain. The Trevi fountain is now, of course, the place you come to chuck in a coin if you want to guarantee your return to Rome, though you might remember Anita Ekberg throwing herself into it in La Dolce Vita (there are police here to discourage you from doing the same thing). Newly restored, it’s one of the city’s most vigorous outdoor spots to hang out. Opposite, the grubby little church of Santi Vincenzo ed Anastasio is the parish church of the Quirinal Palace, and, bizarrely, holds in marble urns the hearts and viscera of the 22 popes who used the palace as a papal residence.