The three most productive targets areas I have ever heard of are: 1) old - and I mean really old - dump sites. You usually have to SIFT, not detect, because of the amount of iron trash, but a fellow local club member who does this almost always finds something of value - old coins (gold ones, too), or Victorian jewelry... 2) beaches, after a strong surf action - storms....and 3) privvy digging. Sounds disgusting, but another fellow club member has unearthed remarkable finds sifting though old outhouse sites - bear in mind that these are many, many years old and no longer are damp...in fact look like plain soil....I am aware of at least four gold coins and a trove of very desirable collectible bottles he has recovered, along with guns, jewelry, and even an old Lionel train engine!