It all began in 303 CE when the Romans executed the death sentence of Efisio, a common soldier guilty of having converted to and professed Christianity. In the high Middle Ages, a sanctuary was built on the exact spot of his martyrdom. Thus the legend began, with the history of the church of Sant'Efisio later taking on more meaning in the late 11th century when it is donated - together with a variety of other places of worship - to the order of the Victorine monks of Marseilles, who rebuilt the sanctuary in the Romanesque style in vogue at the time, reusing sandstone and limestone ashlars from the ruins of the nearby ancient city of Nora.
The church stands next to the lovely Nora beach some 4 km from Pula and owes part of its allure to its position and vicinity to the beach. The interior of the church exudes an evocative and mystical atmosphere thanks to the dim rays of light that filter in from the oculus above the apse and to the long crypt dug under the presbytery, where there is a domed structure which, according to legend, corresponds to exact place the saint was killed and buried.