 In 1920 , the Commission built three experimental <unk> at Le <unk> , <unk> and <unk> , following the principles outlined in the Kenyon report . Of these , the <unk> Communal Cemetery and <unk> was agreed to be the most successful . Having consulted with garden designer Gertrude Jekyll , the architects created a walled cemetery with uniform <unk> in a garden setting , augmented by <unk> 's Cross of <unk> and <unk> ' Stone of Remembrance . After some adjustments , <unk> became the template for the Commission 's building programme . <unk> were required because all three experimental <unk> went over budget . To ensure future <unk> remained within their budget the Commission decided to not build shelters in <unk> that contained less than 200 graves , to not place a Stone of Remembrance in any cemetery with less than 400 graves , and to limit the height of cemetery walls to 1 metre ( 3 @.@ 3 ft ) . 
