Everything Marc said plus the National Archeology Museum.
Athens is probably your best destination airport unless you can get a cheap flight to one of the big European gateways plus a cheap continental flight.
A Bad Day At Sea [with power] Always Beats A Good Day At Work
Carnival: Glory 2004, Destiny 2008, Splendor 2009, Freedom 2011, Valor 2012, Dream 2013
Celebrity: Summit 2011
Princess: Ruby 2010, 2014, Caribbean 2013, Coral 2014