Cemetery overcrowding is an issue that resonates around the world, particularly in its most cramped cities and among religions that forbid or discourage cremation. The reality of relying on finite land resources to cope with the endless stream of the dying has brought about creative solutions.
One space-saving option is to put graves on top of each other, separated by a concrete divider, and have a shared headstone. This is common among couples and even whole families. A second option is stacking the dead above ground into niches built into walls, a bit like in a morgue, but adorned with headstones. A third, revolutionary option is to be buried in a building where each floor resembles a traditional cemetery.
Cemetery towers have been proposed for Paris and Mumbai. In Mexico City, there is another big project in the works: the Tower for the Dead, which will combine a vertical necropolis and an 820-foot-deep (250-meter-deep) subterranean complex. Currently in Mexico City, families are forced to exhume and remove their relatives' remains after a period of years. Unclaimed remains may be reburied as unmarked loose bones beneath the fresh grave, or piled with others on exposed altars.