Re: Greece and Aikido.
I just finished a month rampaging around Greece - alas only a few nights of Aikido. There's a dojo in Thessalonika that I tend to go to when I am in the city - there is only one.
Thermopylae was disappointing - really hard to see anything happening there considering the sea coast had shifted and it looked pretty passable with the highway and all.
Much more impressive was the grave of Philip, father of Alexander the Great and the bronze age ruins of Mycenes which was what I had my sites set on this time round.
Crete (and of course the Minoan ruins) is great and just my luck I found the dojo in Chania just as I was leaving.