The eponymous beach described in "Dover Beach" is a real place. It is on the southern English coast on the Strait of Dover, which marks the boundary between the English Channel to the southwest and the North Sea to the northeast. The beach at this location looks across the water to France.

Matthew Arnold likely wrote the bulk of the poem in 1851, the year he was married, though it was not published until 1867. He evidently based it on the honeymoon trip that he took to Dover with his new wife.

Details in the poem reflect real aspects of the beach at Dover. Looking across at night, one can from time to time see "gleams" of light "on the French coast." The cliffs of Dover are famous for being white, so it is accurate that the speaker would see them "glimmering" in the darkness. Dover has a pebbly beach, as many beaches on the English coast do, which Arnold reflects with these lines:

Listen! you hear the grating roar
Of pebbles which the waves draw back, and fling,

The setting of the poem is real, and Arnold seems to describe images from a visit he really took there. These descriptions are in service of a larger point about the loss of religious faith due to the scientific and industrial progress of the nineteenth century.