Have you ever seen one? They're everywhere. They're so ubiquitous, in fact, that you might not notice them.
Many show where pipes and cables are buried. Some mark property boundaries. The one pictured above is a standard survey marker placed by the National Geodetic Survey of the United States (NGS).
Each survey marker of the NGS is paired with a file in a publicly accessible database that stores a huge amount of geographic data. Other countries have their own versions of the NGS.
Geocaching is a popular pastime worldwide. People establish a container of inexpensive souvenirs for other people to find. Geocachers take an object out and leave one in its place. The fun is in the journey - the searching and finding. There are geocaching websites on the Internet. Check them out...that just might be your next passion.
Survey markers are sorta the postage stamps of geocaching and some geocaching sites have sections about survey markers. Like stamps, they all have more or less interesting backstories on file. For instance, there is a survey marker on a step in the Colorado State Capitol in Denver that shows precisely (and I mean "precisely") where a mile above sea level is.
Last fall, I used a local survey marker as a destination for a hike. I planned to use it for an activity in one of my LabBooks. I found it by using the map search engine, here:
The marker was about two miles away on the other side of nearby Interstate 25.
The marker is on a little concrete mound on a shoulder between an urban street in the Denver Tech Center and the Interstate. There's a stake there to indicate its position.
It was a reasonable urban hike on a nice day.
If you tap (or click) the marker on the website map, you get a link to the data file.
How much information could be attached to such a little metal plate. You'd be surprised. There is position information - latitude and longitude to five decimal places of seconds, and altitude in millimeters. There's also a detailed description of the site and the buildings and streets in the area.
If you want to know your place in the world, a survey marker will tell you.
The map also gives a link to a geocaching site:
There are survey markers associated with monuments, mountain peaks and other geological points of interest, and town squares. If you think you might be interested in benchmark hunting (that's what it's called), check out this site: