Situated on the consular road Adriatic Flaminia, the Bridge of Diocletian was built in the late imperial age by the inhabitants of Anxanum with the purpose of connecting the quarter Prato and the Piano delle Fiere (plain of fairs), which the ditch of the Pietrosa divided. The bridge collapsed after an earthquake in 1088 and was re-built in the thirteenth century in a medieval typology; a chapel consecrated to the Virgin was erected upon it and then restored and enlarged in the following centuries until it became the present Church of the Holy Mary of the Bridge. The church occupied the ground of the bridge and thus became a hallway for merchants who travelled towards the plain of fairs. Finally, in 1520 a vaulted passageway was built under the church and a walkway on its left side. The underground rooms of the churches of the Holy Mary of the Bridge and of Saint Francis contain an exhibition about the building phases of the bridge of Diocletian, the remains of the earliest church of the Eucharistic Miracle and to other local archaeological finds.