I’m a mortician and love this list. Just wanted to add a correction; the sunken in areas are sometimes, but not often, from plots being disinterred. Up until a few decades ago, grave liners weren’t common or mandatory in cemeteries. With time and age, the caskets would break down and the ground would collapse downward. (Unfortunately this happened often, with big machinery coming to dig new plots, so liners became mandatory in most cemeteries).

Grave liners are also popular because during storms, caskets could come to the surface and float. It happened a lot during Hurricane Katrina and Colorado has Coffin Races to celebrate the time one went on a ride through the city during a flood. The concrete liners stop caskets from floating.