You need to google "Countries that allow/do not allow metal detecting/metal detectors. ....
waynokan,welcome to T'net. Yes there's been several attempts , over the years , that people have done to try to make a compendium of laws of various countries. And yes you can google that, and find various forum threads on various md'ing websites where ...at first glance .... you'll find someone who's citing laws, and/or relaying answers they found by asking a border consulate. Thus ... who can argue with sources like these ? But the devil becomes in the details .
The trouble with trying to start a compendium like that, is that a lot of what an ultimate "yes or no" relies on, is NOT cut & dried "no metal detecting allowed" language. Instead, the answer will often rely on ancillary language about cultural heritage. And even when exact language that does indeed address metal detectors specifically , yet only in certain contexts. Ie.: certain forms of land, or certain age-cutoffs, or .... yes as long as you have a permit, etc...
So what you end up with , when doing the google search, is finding lots of places with dire sounding stuff (and/or outright "no's"), yet hobbyists there who ... when using common sense .... are doing it. Thus, oddly, some of the countries that got a "no" on their list, it came as a big surprise to local hobbyists there, who were left scratching their heads saying "since when ?" See how that works ? Thus it's not as easy as googling it.
The psychology of no one wanting to believe good news, and everyone preferring to believe bad news, is heavily at play here. It is only natural to want to believe the "safe" answer. So if you google it and find posts, links, etc... that say "it's illegal", yet you find other posts that say "it's ok", people will tend to side with the ones saying it's not ok. Or at a minimum: They will attempt to "get to the bottom of it". And how best to do that ? Ask yet-another official there. Who in turn couches the pressing question in terms of shipwreck salvor laws, exporting gold bars, raiding the pyramids, etc... And then the vicious loop continues.
TH'r and waterscoop, I am NOT saying this to advance the notion that any particular country is therefore legal. I have no doubt that ... yes ... laws and yes enforcement exists. I am just commenting on the PATH that mdr's go to, do DISCERN the laws.