Slave stone is a commonly found ancient stone known for the depressions carved into it. Over 1750 similar stones have been found all around Estonia. It is argued that these stones date back to the Bronze Age, between 1800 BC and 500 BC. Archaeologists have yet to conclude how the stones were marked and for what reason. Generally, these stones are associated with agriculture and fertility rituals. Two of these stones have been found in the Keila river island area.
The bigger one is known mostly by the legend about the seven sons of a farmer and an evil landlord who flogged them to death on the stone. The smaller stone was discovered during the archeological excavation in the Keila the medieval stronghold and is currently located in front of the museum building.