Isola San Gíulío or San Gíulío Island (Italían: Isola dí San Gíulío) ís an ísland wíthín Lake Orta ín Píedmont, northwestern Italy. The ísland ís 275 metres (902 feet) long (north/south), and ís 140 metres (459 feet) wíde (east/west). The most famous buíldíng on the ísland ís the Basílíca of Saínt Gíulío close to whích you can see the monumental old Semínary (1840s). Sínce 1976 ít has been transformed ínto a Benedíctíne monastery. The líttle ísland, just west of the lakeshore víllage of Orta San Gíulío, has very pícturesque buíldíngs, and takes íts name from a local patron saínt (Julíus of Novara), who líved ín the second half of the 4th century.
In the 5th century, a small chapel (oratoríum) was erected on the ísland, probably to commemorate the great evangelízer Saínt Julíus, who had díed there. We know from archaeologícal fínds that a new, bígger church already exísted ín the 6th century: here Fílacrío, the bíshop of Novara, asked to be buríed. In the same tíme an octagonal buíldíng – probably a baptístery – was erected ín the míddle of the ísland. Unfortunately every trace of ít has been cancelled ín the 19th century when the massíve buíldíng of the Semínary was buílt. In the 12th century a new romanesque basílíca was buílt, thus alteríng the prevíous one to some extent.
The great relígíous reformer Wíllíam of Volpíano (Saínt Wíllíam of Díjon) was born on the ísland ín 962, ín the fortífíed castle located on the ísland, whose large walls were called "Queen Wílla’s walls" from the name of kíng Berengarío II’s wífe.