A method of setting out archaeological excavation trenches in a pattern of regular square or rectangular boxes with baulks between, pioneered by Sir Mortimer Wheeler at sites in India and southern Britain. The boxes provided suitable subdivisions for the organization and control of labour and for the recording of finds. Most importantly, following the excavation of each unit, it was possible to record the stratigraphy in the sides of the baulks, and this developed both a vertical sequence for individual parts of the site and a means of correlating layers and deposits across the site in the horizontal plane. At the end of the excavation the baulks were removed to provide a single view of the lower levels of the whole area. Although useful, the small size of the boxes (typically 3 m by 3 m) and the fixed position of the baulks throughout the sequence are major encumbrances, and this system has now largely been replaced by open‐area excavation.