"Round, metallic looking piece, halfway stuck in the ground, placed in west Germany. Was afraid to get closer. Explosive? I called the police. They cleared the area and send me away."
"Possible anti-armor/tank mine. It looks in good condition and does not have a fuze or place for a fuse. The lack of rust indicates it is either concrete or some non-ferrous metal. It is very similar to a USA produced training mine except it isn’t painted/marked as inert."
...film container. No mine has this particular imprint on the housing. For pressure you install AP or frog type device under, and pressurize with AT.
They are used all over to prevent damage to ships in general.
We use yokohama fenders while repairing the regular fenders on the jetty.