Roughly speaking,any treasure trove is, essentially, the property of the Crown, which is then shared with the landowner and the finder get some monetary value or if there is a stash of coins he may get get one as a keepsake. Usually the local museum houses the treasure find if it is considered 'not uncommon or unusual', but real rare items are housed in one of the London Museums. As I say, this is a very rough interpretation of the law. If there is someone who knows more about this, please enlighten me.