If searching for recently lost coins, then it may not make a significant difference where in a large park or other detecting location you decide to search. If you are looking for the older, often more valuable finds like silver coins or relics, then where you decide to search is really important.Over the last several decades, much of the landscape of a certain location may have been altered. Sometimes this is favorable and other times it is not, as is the case with fill dirt.Let me give a few examples to illustrate this point. A few weeks ago, I was metal detecting at the location of an old high school that had originally been built around 1914. A few years back, the school was torn down and a new one was built in its place. It was obvious that the area around the new school had been significantly altered and so I did not spend much time around the building. I decided to try some of the areas around the ball fields, hoping that the areas were old. After digging a few copper memorial cents at around 8-9 inches, I decided to pay close attention to the dirt as I dug. The top inch and a half had a lot of sand and appeared to be more recent fill. Below that was about a six inch layer of really rocky dirt and below that was a mixture of other dirt. This is where I was finding the memorial pennies. At this point, I did not thoroughly grid off any areas. Instead I dug some sample targets around the field, especially the low spots. Almost all of the areas where the same on this field. Then, I dug a target closer to the baseball field and noticed that it had the thin layer of sand but not the rocky gravel. There was a darker soil only a few inches down. I carefully worked this area and pulled out a silver quarter.After reworking this area with a smaller and larger coil, I noticed that this darker soil had pieces of red clay like dirt that looked like old baseball infield dirt mixed in. It was not an even mix, as the clay was in clumps. I did find some recent coins as I reworked this patch, but only found recently lost coins. Later, I met a guy who pointed out where the fields where when he went to school. Apparently the field I was working had been paved and was the driving range. They brought in fill dirt and turned it into an extra practice field. The old baseball diamond is now a parking lot. This, I guess, is where the quarter came from. I suspect that in this small patch, they had to use some of the old baseball dirt to finish the job. The lesson learned: If I had not paid attention to the ground and asked questions, then I could have spent days searching the field without much success. Instead, I was able to move onto more productive areas where the potential for old finds is greater.Similarly, when gold prospecting with a metal detector, if the layer of dirt above bedrock is well beyond the depth capabilities of your metal detector, then might be spending a lot of time on ground where the gold is too deep to find. Paying attention to soil types and depths will help you to find more of the good stuff and waste less of your valuable time.