The Church of Santa Maria Forisportam is commonly known as the church of Santa Maria Bianca for its marble structure in white limestone. It is located in Piazza Santa Maria Bianca in the historic centre of Lucca, although it was originally situated outside the Medieval walls (hence its name) from where it was incorporated into the city probably in the 12th century, in the period of its reconstruction. Although it recalls the model of the Cathedral in Pisa, the church differs in the particular construction details of the pilasters and the columns which support the windowless arches in the façade in the side and the apse. Some works remain incomplete, in the 16th century the church underwent continuous modifications: it was built in brick and the vaulted roof and the large circular windows were constructed over time. In 1618 the bell tower was completed, but other restoration projects were also carried out during the course of 18th and 19th centuries. It was interesting to note how inside the church you can find a “darkroom” sundial: on the high western part there is a hole for light while the hour line is drawn on to the floor. At the intersection of the shaft of light with the hour line you can see that the sun has reached its maximum height, indicating the true midday point of the place which occurs at 7 minutes 55 seconds behind the Roman winter time.
Source: comune.lucca.it