Nicopolis means Victory City in Greek and it is what Octavian built after taking part in battles in the nearby area. It is now in ruins but they are extensive. It must have been a fabulous city in its heyday. It housed a significant portion of the population of Lefkás as well as being the major city for trade, administration and religion in the surrounding vicinity. You can find details about the building of the city in the Archeological museum In Lefkás Town.
The city dominated until the middle age when the current city of Preveza starts to become prominent. Nikopolis then becomes known as Old Preveza. There is museum on the site dedicated to the finds found in previous archeological excavations.
This is the most well known historical site in the region as its power was immense and stretched out for approximately a thousand years. The Wikipedia article on Nikopolis is quite lengthy and you get articles in travel magazines from as far afield as Crete documenting the importance of this to the locality.
I will write again about this once I have actually visited as I plan to do soon with hopefully lots of pictures. I just thought this was important enough to write about twice.