We will never be able to excavate everything – nor should we – but it would be good to know how to make the best use of what is visible in the landscape to write social prehistories. In this project the author creates a set of parameters for the 1000 mound-cemeteries seen north of Lake Mälaren and clusters them by period, using 51 examples that have been excavated and dated. The result is that 1000 cemeteries can now be allocated to period, with that special kind of confidence in which statisticians rejoice.