The most famous square of city is characterized by a strange butterfly layout whose ideal centre occupied by one of the less ostentatious Baroque fountains, the Barcaccia Fountain, Designed by Pietro Bernini, the father of the more famous Gian Lorenzo, on commision by Pope Urbano VIII in 1629, fountain is decorated with the coat of arms of the Barberinis, the family and according to a legend is a replica of a real boat which ran aground here during an spate of the river.The piazza owes its name to palace of the Spanish Embassy, situated in front of the "Colonna dell'immacolata".The presence of this coloumn with the palace of Propaganda Fide has always given a religious connotation to this piazza, which in fact has always been a focal point of Rome's artistic and social life.