Well, el padron, I notice you don't cite any law that's actually saying "no metal detecting". But are just going by the intuition that is natural, that *any* country with such spell-binding ruins, simply *MUST* have some sort of border-to-border prohibition? Maybe yes, maybe no.
But it's all relative, when you think about it. Because SO TOO is the U.K. and the USA riddled with "historic" sites, depending on who you ask. Like how is Stonehenge any less magnificant. How is Mel Fisher's fabulous discovery (for which he underwent all sorts of scorn and legal hassles) any less historic or valuable? Etc... So TOO does the USA and the UK have prohibitions about certain types govt. land (why do you think UK hunters do 99% private farmer's lands afterall? )
In the USA, in some places (federal and some state level stuff) the age-cutoff is "50 yrs" to be considered a "historical artifact". Hmmm. And I can gaurantee you that you can find some archies here who might say you can't detect any public land, whatsover, on any level (and maybe even find dire-sounding verbage that appears to back up what they're saying). But the *reality* is, that it's probably only those couple of ivory tower archies who could dream up or care about such things, and you're right: You just avoid those "one or two" who might gripe, and no one else (certainly not the farmer you're about to go 50/50 with) cares less.
I'm not saying to "throw caution to the wind" and tromp of sensitive places, etc... But just saying that sometimes you have to read between the lines. Like right now, I bet you, there's no doubt hobbyist in Greece. Presumably doing their hobby legally *somewhere* Or .... with the ... uh ... "presence of mind" to not be an eyesore knowing how not-to-ruffle someone's feathers.
The antiquities laws have gotten pretty insane. When they built the Subway in Athens in preparation for the Olympics about 12 years ago or so they found so many artifacts that every station has a museum in it.
They would simply pour a concrete frame around whatever it is they found, (an ancient tomb, or somebody's front door from 2500 years ago ) and cover the entire wall floor to ceiling with a 1 inch thick piece of plexiglass.
Right about that time, the national antiquities service went into full gear and started investigating every single new construction project in the city of Athens.
So today, if you visit Athens, literally every block or so is a coned off archaeological no mans land with the familiar blue and white tarp over it.
On the islands the antiquities laws are enforced in the name of national security
Modern Greece is a very young country. They just received independence from the Turkish Empire in 1821, it took until a few more years after that for the rest of the world to recognize them as a sovereign nation.
From the perspective of national security they are very paranoid, in all my visits there I have never once seen a metal detector
On the islands, (I've only been to two) I have been sternly admonished to stop taking pictures many times.
I can only imagine what they would do if you were spotted swinging a Garrett ATX looking thing around on the sand, which they often construed as a border zone of sorts in accordance with whatever it is they are trying to convey or support at the time.
@Bmontym personally I think it would be a really great opportunity to do some metal detecting in Crete, and who knows, you might get away with it on a crowded beach, I don't know. It would be great if you could bring a folding metal detector there, (though that's a pretty tall order as far as mainstream metal detectors go,) and revisit this site upon your return and tell us what your experience was.