text: This building's piazza is defined by a colonnade of double Tuscan columns that grow into an enormous elliptical circle.
full_question: This building's piazza is defined by a colonnade of double Tuscan columns that grow into an enormous elliptical circle. This building contains a reconstruction of Giotto's depiction of Christ walking on the water, the Navicella. Its piazza contains an Egyptian obelisk known as "The Witness" as well as a fountain designed by the creator of this building's facade, Carlo Maderno. Bramante drew the original design for this building, before it was modified by Michelangelo. Pope Urban VIII hired Gian Bernini to complete, for 10 points, what massive church at the heart of the Vatican City?
first_sentence: This building's piazza is defined by a colonnade of double Tuscan columns that grow into an enormous elliptical circle.