This extraordinary oval-shaped piazza buzzes with life day and night.
I was once asked by a bunch of Italian lads from the country where "the piazza" was (their town clearly only had one). Rome has so many that I was stuck for a moment. Then I realised Piazza Navona would fit the bill nicely. This magnificent oval – its shape determined by an ancient athletics track – is where Romans stroll in the early evening, tourists hang out all day, street vendors and entertainers are to be found through the night and there's always something to observe.
The Emperor Domitian was responsible for the original athletics track, some remnants of which can still be seen in a fenced-off area immediately to the north of the square. This was, legend says, where St Agnes was martyred: the church of Sant'Agnese in Agone, on the west side of the piazza, was designed by Borromini.
The first-century AD arena was in a ruinous state when it was remodelled in the 17th century. Gianlorenzo Bernini's Four Rivers fountain (1651) at the centre of the square shows the rivers Ganges, Nile, Danube and La Plata, each of them with appropriate plants and animals from their respective continents. The myth that the Nile (the west-facing one) had its face covered because Bernini couldn't stand Borromini and hated his church is no more than that: a myth. The cover signifies that the source of the Nile was unknown... and Sant'Agnese was built after the fountain was completed.
The glitzy cafés surrounding the square tend to be mediocre but hugely expensive, especially if you sit at a pavement table to watch the world go by. But if you can't take it all in without a cappuccino, just think of it as a tax on a stunning view.