It's the busiest and liveliest street of Lucca and his "parlor". This street, rich in commercial activities leads the visitor to Piazza Anfiteatro and, a little later, to Piazza San Frediano where stands the Basilica of the homonymous saint and Bishop of Lucca.

Via Fillungo is part of the original Roman structure for urban roads. The third part of Via Fillungo is part of the ancient "cardus" in North-South direction, along with its natural continuation of Via Cenami. 
Part of the ancient "decumanus" (perpendicular to the cardus), in West-East direction are instead Via San Paolino, Via Roma and Via Santa Croce, until Via Elisa (which however has been built receltly).