My worst was a 24-er 2nd WW RAF bomb near a Hamburg playground, in a small forest we just opened for the kids to play in. I was team member of the forestry that time. Not very nasty (esthetically looked) but on the other hand... I had to take it into my car and drive away a bit (then I called the cops), for there was no chance to wait for the police or someone better experienced, as the children all wanted to see (and touch, I suppose even taste) it...