Here's a full photo of it: https://commons.wikimedia.org/wiki/File%3AMetal_geodetic_marker_-_survey_beacon_near_%C4%B6ekava%2C_Latvia.jpg

It does indeed appear to be an old geodetic marker - survey beacon. Those discs/plates are likely to make it visible from the air for aligning.

There are no markings or labels on it anywhere. It's on top of a "kupica".