Piazza Navona was built on the site of the 1th-century Stadium of Domitian and follows the form of the open space of the stadium. Defined as a public space in the last years of 15th century, when the city market was transferred there from the Campidoglio, Piazza Navona was transformed into a highly significant example of Baroque Roman architecture and art during the pontificate of Pope Innocent X. He reigned from 1644 until 1655, and whose family palace, the Palazzo Pamphili, faced the piazza. It features important sculptural and architectural creations like the famous Fontana dei Quattro Fiumi (1651) by Gian Lorenzo Bernini, topped by the Obelisk of Domitian, brought in pieces from the Circus of Maxentius.
Piazza Navona has two other fountains. At the southern end is the Fontana del Moro with a basin and four Tritons sculpted by Giacomo della Porta (1575) to which, in 1673, Bernini added a statue of a Moor, or African, wrestling with a dolphin. At the northern end is the Fountain of Neptune (1574) also created by Giacomo della Porta; the statue of Neptune, by Antonio Della Bitta, was added in 1878 to create a balance with La Fontana del Moro.
During its history, the piazza has hosted theatrical events and other ephemeral activities. From 1652 until 1866, when the festival was suppressed, it was flooded on every Saturday and Sunday in August in elaborate celebrations of the Pamphilj family. The pavement level was raised in the 19th century, and in 1869 the market was moved to the nearby Campo de' Fiori. A Christmas market is held in the piazza.References:
The city walls of Avila were built in the 11th century to protect the citizens from the Moors. They have been well maintained throughout the centuries and are now a major tourist attraction as well as a UNESCO World Heritage Site. Visitors can walk around about half of the length of the walls.
The layout of the city is an even quadrilateral with a perimeter of 2,516 m. Its walls, which consist in part of stones already used in earlier constructions, have an average thickness of 3 m. Access to the city is afforded by nine gates of different periods; twin 20 m high towers, linked by a semi-circular arch, flank the oldest ones, Puerta de San Vicente and Puerta del Alcázar.