Bolsena is a town and comune of Italy, in the province of Viterbo in northern Lazio on the eastern shore of Lake Bolsena. It is 10 km (6 mi) north-north west of Montefiascone and 36 km (22 mi) north-west of Viterbo. The ancient Via Cassia, today's highway SR143, follows the lake shore for some distance, passing through Bolsena.
The Roman historian Pliny the Elder said that a bolt from Mars fell on Bolsena, "the richest town in Tuscany" and that the city was entirely burned up by this bolt. The population moved to another site, which Dennis thought was Bolsena. The new city was named after the old, hence Roman Bolsena has an Etruscan name. Dennis suggests a number of crags in the area including Orvieto but does not favor Orvieto on the grounds that it is too far away.
Bolsena is known for a miracle said to have occurred there in 1263, when a Bohemian priest, in doubt about the doctrine of Transubstantiation, reported bleeding from the host he had consecrated at Mass. The Orvieto Cathedral was eventually built to commemorate the miracle and house the Corporal of Bolsena.