hi and welcome..the only way through public transport is via the inercity bus named KTEL...i am not sure how far the KTEL bus station is from the port and how you will get there ,hoping someone else can help with that..the bus will leave you at kifissos bus station , in athens..since you will arrive late at night catch a taxi from kifissos station to your hotel in athens..for things to do in athens the options are so many..if you can be more specific about what you want to do we can help you more..
take a look at these threads,and since you want it to be relaxed,give yourself much time and don't cram in too many activities
forget my Ιast post..i did a quick check at the bus schedules from patras to athens..
assuming the site is up to date you won't make the last bus,there is only one at 22.00 on sundays ,so it seems like an overnight in patras is the only way..maybe look for a nice hotel near the port and the next morning you can head to athens with the whole day in front of you..Edited: 23 December 2013, 00:03
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