Siena's historic centre sorely lacks backpacker accommodation, so we were thrilled when this hostel just off Piazza Duomo opened in 2017. Though primarily catering to pilgrims walking the Via Francigena, it also welcomes others – book in advance. Rooms have bunk beds and small lockers (sheets and blankets provided); hot showers cost €0.50. Laundry facilities (charged), but no kitchen or lounge.
Note that daytime check-in is at the Tourist Office in Santa Maria della Scala; the hostel is only staffed between 8pm and 10.30pm.