The Basilica of San Francesco stands beside Dante's tomb and provided the setting for the poet's funeral in 1321. The church itself is a 10th-century structure, rebuilt several times, with a calm Romanesque interior that is often overlooked by visitors who come only for the tomb. But the real reason to go inside is the crypt.
The crypt of San Francesco is one of the strangest spaces in Italy: an early Christian burial chamber, dating from the 4th or 5th century, that has been partially flooded by the water table. A few centimetres of clear water covers the ancient mosaic floor — fragments of the original pavement are still visible beneath the water — and goldfish swim over the tesserae in the cool, greenish light. The effect is genuinely uncanny: a sacred space that has been colonised by ordinary nature in a way that dissolves the usual distance between the ancient and the living.
Access is through a small opening in the church floor, usually with a viewing area around the edges. The descent is steep; the chamber is small. It is free to enter the church, with a small fee for the crypt.