There is a hot spring approximately 80 kilometres north of Rome that has been in continuous therapeutic use since the Etruscans. The Romans called it Aquae Passeris. The medieval popes, who retreated to Viterbo throughout much of the 13th century to escape the politics of Rome, maintained a papal residence 3 kilometres down the road from it. The water emerges from the ground at 58°C, smells of sulphur, and contains enough dissolved minerals that a 20-minute soak carries a perceptible physical effect on muscles that have recently covered 26.2 miles.
The FL3 Trenitalia line from Roma Ostiense station runs northwest into the volcanic Cimini hills and reaches Viterbo in 1 hour 30 minutes. Trains run roughly every hour. Ostiense station is accessible from Termini via taxi (approximately €10). Viterbo station is in the modern town, a flat 10-minute walk from the medieval walls.
Viterbo: The Papal City
Viterbo is a walled medieval city of 65,000 people built on tufa - the compressed volcanic ash that ancient eruptions deposited across northern Lazio. The walls are largely intact. The Quartiere San Pellegrino - the medieval quarter - is one of the best-preserved medieval urban spaces in central Italy: narrow stone lanes, external staircases, covered bridges between buildings, and the atmosphere of a city that had its architectural zenith in the 13th century and has been well-maintained rather than dramatically altered since.
The Palazzo dei Papi (Papal Palace) on the Piazza San Lorenzo was the official papal residence during the period when the papacy relocated to Viterbo (1257 to 1281). The longest conclave in papal history occurred here: after the death of Clement IV in 1268, the cardinals assembled and failed to elect a successor for nearly three years. The citizens of Viterbo, running out of patience, locked the cardinals in, then removed the roof to expose them to the elements, and finally reduced their food to bread and water. This produced Gregory X in 1271, who subsequently established the conclave rules still used today.
The historic centre is largely flat within the walls on the plateau.
The Terme dei Papi
The Terme dei Papi spa complex sits 3 kilometres northwest of Viterbo, accessible by local bus (Line 11, approximately 15 minutes from Viterbo station) or by taxi (approximately €10 from the station). Pope Nicholas V bathed here in the 15th century, and the therapeutic reputation predates the papacy by several centuries.
The main outdoor pool - the Piscina Termale - is approximately 2,000 square metres of natural thermal water maintained at 58°C at the source and cooled to around 37°C in the main bathing pool. The water is milky white from dissolved minerals and smells distinctly of sulphur. The effect on muscles worked to their limit 24 hours previously is consistent: a sustained heat penetration into the deep muscle tissue that a hotel shower cannot replicate.
Entry to the outdoor thermal pool costs approximately €17 to 22 depending on the day and season. The facility opens at 09:00 on weekdays. Booking is not required for the outdoor pool; a Monday visit after the marathon will typically be uncrowded.
March at the thermal springs: The outdoor pool is most enjoyable in cooler weather. The steam rising off the surface at 37°C against the March air temperature of 10 to 14°C creates the correct thermal atmosphere.
Where to Stay and Eat
The Grand Hotel Salus e delle Terme at the Terme dei Papi complex is the obvious choice - rooms directly adjacent to the thermal facilities.
For dinner in Viterbo: Il Grottino on Via della Cava, in a vaulted stone cellar within the San Pellegrino quarter, serves traditional Viterbese cooking - acquacotta (the local bread and vegetable soup) and fagioli con le cotiche (beans with pork rind, slow-cooked). Neither dish aspires to sophistication; both are exactly right for the day after a marathon.
Practical Notes
Return trains from Viterbo to Rome Ostiense run throughout the day. The Tuesday morning service connects with Termini and the Leonardo Express to Fiumicino Airport if needed. The steep climb to the Rocca Albornoz (14th-century papal fortress above the town) is not recommended on post-marathon legs.