Stone of Remembrance
The Stone of Remembrance was designed by the British architect Sir
The initial thoughts for the design were sent by Lutyens in letters and memoranda in May and August 1917 to
On platforms made of not less than three steps... place one great stone of fine proportion 12 feet long and finely wrot – without undue ornament and tricky and elaborate carvings – and inscribe thereon one thought in clear letters so that all men for all times may read and know the reason why these stones are placed throughout France – facing the West and facing the men who lie looking ever eastward towards the enemy.— Letter from Lutyens to Ware in May 1917, quoted from Lutyens and the Great War (2009) 
Part of the design is the three-stepped platform on which each stone rests. Architectural historian
...one great fair stone of fine proportions, twelve feet in length, lying raised upon three steps, of which the first and third shall be twice the width of the second.— Memorandum from Lutyens to Ware in August 1917, quoted from Silent Cities (1977) 
In a later work in 2006, Stamp identifies a similarly abstract and geometrical concept that was part of Lutyens' creative process, citing a letter that Lutyens wrote to his wife while on the July 1917 visit to France, describing how a 'solid ball of bronze' could be used to make a permanent monument. 
By the time of Ware's 1937 report, published as The Immortal Heritage the same year, some 560 Stones of Remembrance had been erected for World War I cemeteries and memorials in France and Belgium alone.