The Ha-ha is a unique feature in the Museum's grounds and dates from the time the Museum was a family home.
From the 1780s the Museum building was lived in by Mrs Betty Shudd and her orphaned niece, Mary Anne Sanderson. In 1978 Mary Anne married the Reverend Doctor Robert Price and over the next 15 years they laid out the garden as pleasure grounds for the family to enjoy the outdoors. It is likely that they had advice from Dr Price's brother Uvedale Price, 1st Baronet of Foxley, who was a great supporter of the picturesque style of landscaping, which favoured retaining old trees, rutted slopes and textured slopes.
The Ha-ha was added at the same time as the pond and gazebo. It is a sunken wall and ditch designed to stop livestock from getting into the formal gardens without spoiling the view as a fence would. It is believed that the name came from the surprised exclamation that people would make when coming across the ditch ('ha-ha, there it is!')