Detecting Japan

These are the oldest of the few coins I found in Japan. The country seems to be virgin to detectors, but the problem there is finding an undisturbed place to hunt. All of these came from old shrines or temple grounds. The smallest coin dates to 1620 and the mid sized one to 1861. There are no markings on the other side of these two. The large coin (about the size of an American half, both sides shown) is 1870 vintage. By then, arabic characters had started showing up on their coins. This was the neatest of their coins that I found with the dragon on the front and the wreath on the back.

I was hoping to find a silver coin, but the Japanese guys I worked with said having a 100 yen coin in those days (pre-WW2) was rare.