Preveza is a city in the region of Epirus, northwestern Greece, located on the northern peninsula of the mouth of the Ambracian Gulf. It is the capital of the regional unit of Preveza, which is the southern part of the region of Epirus. The Aktio-Preveza Immersed Tunnel –the first and so far only undersea tunnel in Greece– was completed in 2002. The immersed tunnel connects Preveza in the north, to Aktio of western Acarnania to the south. The ruins of the ancient city of Nicopolis lie 7 km north of Preveza.