Chiesa di Santo Stefano dei Cavalieri faces Piazza dei Cavalieri and was designed by Giorgio Vasari in the 16th century for the Order of Saint Stephen. The order was founded by Cosimo I de' Medici as a naval and chivalric order, and the church still helps explain why this square feels so carefully staged.
It is easiest to visit while walking between the Leaning Tower area and central Pisa. The exterior and setting are the main draw, especially if you are already pausing for Piazza dei Cavalieri.