> That doesn't seem to happen in England, which allows metal detecting.
In England you need permission of the landowner (or which ever authority is responsible for a piece of public land) and must report any archeological finds. There's a lot of illegal metal detecting at night - "Nighthawking", and fairly tough convictions.
Laws requiring permission from the land owner to use a metal detector and dig vs. needing such permission on your own land seems very different IMO.
The English law seems focused on preventing trespassing and digging holes in people's yards, and also to make sure the land owner gets compensated for anything of value found. (e.g. from the link by madax below: In England "An experienced detectorist, Davies would have known he was entitled to half of the proceeds of legal sale of the treasure, instead choosing to deprive the landowner and public by stealing this exceptional and significant treasure.")
The Irish law seems focused on preventing anything from being found.
There is also a fair bit of anger against FLOs (Find Liaison Offers) that the finds are reported to. Detectorists often get low-balled on the value of their find (after a 2 year wait) to make the item affordable for local museums.
In England you need permission of the landowner (or which ever authority is responsible for a piece of public land) and must report any archeological finds. There's a lot of illegal metal detecting at night - "Nighthawking", and fairly tough convictions.
https://en.wikipedia.org/wiki/Nighthawking
https://www.bbc.com/news/uk-england-humber-68445207