I always look for old postcards of local places when at the flea markets & antique shops to use as a tool in my metal detecting. Here is a postcard from Hill NH taken in the 1930s or early 40s compared to a picture taken recently. The entire town was moved uphill in 1941 when a dam was built on the river to control flooding. 3 churches, gas station, stores, factories, school, train station and repair shop, as well as several homes all either moved a mile or so away or destroyed. The unfortunate part of the story is that the site is maintained by the Army Corps of Engineers and depending on which ranger you run into metal detecting may or may not be allowed. My point though is don't overlook old postcards as a treasure hunting tool. First pic is the "before" pic. 2nd pic is what the same spot looks like today... The good news is that you would assume the coins would date to 1941 & before and the town was founded in the mid 1700s. The bad news is that local kids have been partying there since the invention of beer and the last time I was there all I found was clad and memorial cents & ALOT of beer cans