Suggestions for things to do in/near Portland and Kennebunkport Main?

[JoeM]

The wife and I have a wedding to attend near Kennebunkport ME in mid October. We'll fly up to Portland 3 days ahead for sightseeing and hopefully some photography for me. The wedding is at The Atlantic Hall in Cape Porpoise and we'll stay a couple of miles from the hall that night and day but we thought we'd stay somewhere else, maybe near Portland for the prior 3 days if there are more interesting things to see in that area.

Is anyone familiar with the area and if so, any suggestions for where to stay nearby for sightseeing and what might be fun to check out?

TIA