The Pisa Baptistery of St. John is a Roman Catholic ecclesiastical building in Pisa, Italy. Construction started in 1152 to replace an older baptistery, and when it was completed in 1363, it became the second building, in chronological order, in the Piazza dei Miracoli, near the Duomo di Pisa and the cathedral's free-standing campanile, the famous Leaning Tower of Pisa. The baptistery was designed by Diotisalvi, whose signature can be read on two pillars inside the building, with the date 1153.
