Piazza Navona is long and rounded at one end because it sits exactly on top of an ancient stadium. Here's what you're looking at, and what to listen for as you cross it.
Domitian built a stadium here for athletic games around AD 86. When it crumbled, houses were built on its stands, so the square kept the exact outline of the track. Below the north end you can visit what's left of the stadium itself.
The obelisk on Bernini's fountain looks Egyptian, but it was carved in Rome for Domitian, with hieroglyphs written for a Roman emperor. Bernini brought it here from the Circus of Maxentius on the Appian Way.
From 1652 to 1866, on August weekends, the drains were blocked and the square was flooded so carriages could splash through it and crowds could watch from the windows.
It follows the outline of the Stadium of Domitian, built around AD 86, whose stands were later turned into houses.
The central Fountain of the Four Rivers is by Gian Lorenzo Bernini, completed in 1651. The two fountains at the ends are older, from the 1570s.
No. It's Egyptian in style but was made in Rome for Emperor Domitian, and moved here from the Circus of Maxentius.