The exterior of the baptistry was reworked in Romanesque style between 1059 and 1128. The surviving frescoes of the baptistry room are probably the most ancient Christian paintings. The surviving frescoes of the baptistry room are among the most ancient Christian paintings. It appears on the baptistry of the Siena Cathedral in Italy. The church has four confessionals and a marble baptistry. Unlike Florence or Pisa, Siena did not build a separate baptistry. The legend is commemorated in the Minster's baptistry window. Also on the main floor is the baptistry, where vicarious baptisms are performed. The importance of water baptism in Christianity was reflected in the scale of baptistry architecture. The church contains a baptistry heated by hypocausts. In many Baptist churches, a large cross hangs above the baptistry. But when the baptistry was built, this under-church was filled with rubble. To the right of the entrance a small room was made into a baptistry. The baptistry was built in its place. A sealing room and small baptistry are also included.