Casperia is between the left bank of the Tiber and the western slopes of the Sabine Mountains. The Latin poet Virgil mentions it in the 7th book of the Aeneid. However the origins of Casperia are uncertain. The village that we can see now was certainly founded with the name Aspra in the 11th Century – this is what it was called until 1946. In the countryside olive groves reach to the horizon which produce Sabine extra virgin olive oil. Up in the Sabine Mountains above Casperia you can find the permanent spring known as Fonte Cognolo at 1,054 metres above sea level and some of the highest of the peaks in this mountain range. In the parish of Casperia there are four monumental trees: the holm oak of Aspra, the nettle tree on Montefiolo, the beech at Fonte Cognolo and the oak in Valle Ferrara. The historic centre of Casperia is a typical example of a medieval village: walled walls with towers and forced entrances, the streets are in concentric circles which get smaller and smaller as you go up the hill to the top where the piazza of San Giovanni Battista is with its church and its monumental bell-tower. Here at the top of the village was were the medieval fortress of Aspra was first built. The village can be accessed only by foot through the two gates (Romana to the southwest and Reatina to the northeast), inserted in the city walls of the end of XIII century.