The Pisa Baptistery of St. John (Italian: Battistero di San Giovanni) is a Catholic ecclesiastical building in Pisa, Italy. Construction started in 1152 under the direction of Diotisalvi (signed and dated) to replace an older baptistery. Completed in 1363 in a Gothic manner, it is part of the architectural ensemble and World Heritage Site of the Piazza dei Miracoli, alongside the Duomo di Pisa, its campanile, the famous Leaning Tower of Pisa, and the Camposanto.