Round earth and/or stone works raised over a burial. They started occurring in the Neolithic and were very common in the early Bronze Age. They continued to be built up to and including Anglo-Saxon times.
Fact of the Day
In 1506 the Principal of Magdalen Hall, Oxford, was accused of baptising a cat as part of a conjuring ritual to find buried treasure. He later became Bishop of London and a notorious heretic hunter, and was mockingly known as 'Bloody Bishop Christen-cat'.