re.: inner-city urban parks for gold:
There was a retired elderly guy in my city who .... in his older years, had slowed down enough that he wasn't able any longer to do any exotic hunting, or long drives, or very strenuous lengthy hunts. But he loved md'ing enough that he wouldn't give it up, till his very last days when he simply couldn't physically get out anymore.
And for that last several years of his hunting, he was simply going to all the sandboxes, tanbark boxes, etc.... of all the parks and schools around our city. He had a route, where .... in a month's time, hitting 3 or 4 spots, for a few mornings per week, that he'd eventually hit them all, all over town. And then start over the following month to repeat. Such that he kept them "cleaned out".
He and I were shooting the breeze one day gabbing, and I played the devils' advocate and said "... but you're never going to get any old coins doing that" . To which he said his angle was for jewelry. And he proceeded to show me all the gold statistics, in his record keeping, year by year, of doing nothing but sand and tanbark. And by golly, he was getting some gold on average about 2x or 3x p/month or whatever. Sure, maybe just trinkets or charms, and an occasional ring. But by the time he'd have it all added up by the end of the year, it was about 20 quality rings, other gold misc., a smattering of silver items, etc.... And then throw in all the clad he'd accumulate, and by the end of the year, it amounted to a fun sum.
But this guy was not trying the same tactic in the turf. Which would require all that sod-digging (risking the ire of the park's people) and instead preferred the sand and tanbark. Which was fast action easier digging, and perhaps simply more suited for "frolicking motions" of the hands, etc... in his opinion.