It owes its name to the Palace of Spain, seat of the embassy of the Iberian State to the Holy See since 1622. Seen from above it appears like the shape of "butterfly wings", formed by two triangles with a common vertex. In the center of the square there is the well-known Barcaccia fountain, which dates back to the early Baroque period, created by Pietro Bernini and his son, the more famous Gian Lorenzo. On 8 September 1857 Pope Pius IX inaugurated the Column of the Immaculate Conception which presides over Piazza di Spagna in memory of the definition of the dogma of the Immaculate Conception.