Hiring a car is an option, there is a car hire place near the port.
We booked George and he was excellent. A taxi driver, he took us to Olympia, into the village, on a tour round the area, we picked fresh oranges and figs and then went onto the winery. We didn't have much time there but enough for my husband to do a little wine tasting. The winery is only about 5 minutes away from the port so you wouldn't see much of the country side.
Take a look at George's website. Even if this is not for you, his site will give you some other ideas of what you can do in port.