The chapel, octagonal and surrounded by a portico, was completed in 1659. The group of sculptures depicts Saint John the Baptist, who is baptizing Jesus in the Jordan River, while the Heavenly Father looks from above. The basement of the building houses a cistern, which was used until the late 19th century, to quench the thirst of pilgrims, and later, as a natural ice chamber. The presence of water has also a strong symbolic meaning, being related to the baptismal rite, described inside the chapel.
