One of my professors used a method called GPR to locate old coffins in the ground. He should us the results in class and it was super interesting. One of my coworkers actually just did a similar project.

This is also why I want to donate my body to a body farm. My coffin won’t be in the way somewhere people want to develop on, or my urn gets stored away in a random attic. Just let nature do it’s thing, and have some students study my decomposition.