UK
WW2 bombs still a common find
Thanks to a Freedom of Information request responded to last year, we can see that there is still a considerable amount of ordnance being uncovered, even over 70 years since the last bomb was dropped. Of course, the vast majority of devices disposed of (by 11 Explosive Ordnance Disposal Regiment RLC) are of German origin, but every now and then a British or American bomb is also unearthed.

Description
This chart shows the number of World War Two air delivered ordnance that was disposed of in the UK from 2010 to 2017, by origin.