Porta San Giovanni is San Gimignano's most beautiful and impressive gate. It opens onto the Piazzale dei Martiri di Montemaggio, where the Convent of Saint Francis formerly stood.
It gave access to the city from the south and was the historic access point for those coming from Siena along the stretch of the Via Francigena that passed through San Gimignano.
Completed in 1262, it has a Sienese arch, with a sentry at the top that sticks out and rests on the lower wall with its series of small arches.
In 1601 the sentry was in the doorway to the small church of Madonna dei Lumi, which was demolished in 1922 to clear the road. Today, all that remains of the church is a small bell tower that can be seen beyond the walls.