The Three Tremblers are three adjacent round barrows, the tallest about 3m high. They are in The Tabular Hills in Wykeham Forest - an area which contains a large number of prehistoric monuments from Neolithic to Iron Age times.
But why are they called the Three Tremblers? Someone must have a story to explain. Perhaps if you sit on them you can feel strange goings-on beneath the ground. Perhaps this whole region is a bit strange - well it would explain the large number of barrows here (Or perhaps it's got nothing to do with it).