This piazza is a marvel of light and sculpture. It is exceptionally long and owes its shape to the ruins that formed it, for under the buildings that surround Piazza Navona are the remains of the Circus Domitianus, Domitian's stadium -- a part of which can be seen if you leave the piazza by the north exit and turn left. The piazza marks the area for the races in the stadium. It features many fine old buildings, a beautiful church and three stunning fountains. (Normally one would be happy if a piazza even had just one.)