The Baptist Church of Pisa, also known as St. John's Baptist Pool (Battistero di San Giovanni), is the Roman Catholic Church building in Pisa. It was built in 1152 and is the second ancient building on Pisa's Miracle Square (Piazza dei Miracoli), located between the cathedral and the bell tower. The bell tower is the famous Leaning Tower of Pisa. The Baptist Church was designed by Diotisalvi and can be seen on two pillars in the building, dated 1153.