The —, war memorial in Whitehall designed by Sir Edwin Lutyens (8)

I believe the answer is:

cenotaph

(Other definitions for cenotaph that I've seen before include "Monument to the war dead" , "construction in Whitehall" , "Monument honouring the fallen" , "Monument honouring persons buried elsewhere" , "Whitehall memorial" .)

I've seen this clue in The Mirror.

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