The King of Elfland's Daughter by Lord Dunsany

As the evening that followed was beginning to fade a traveller might have been seen approaching the marshes, which some way southeastwards of Erl lay along the edge of the farmsteads and stretched their terrible waste as far as the skyline, and even over the border and into the region of Elfland. They glimmered now as the light was leaving the land.

So black were the solemn clothes and the high grave hat of the traveller that he could have been seen from far against the dim green of the fields, going down to the edge of the marsh through the grey evening. But none were there to see at such an hour beside that desolate place, for the threat of darkness was already felt in the fields, and all the cows were home and the farmers warm in their houses; so the traveller walked alone. And soon he was come by unsure paths to the reeds and the thin rushes, to which a wind was telling tales that have no meaning to man, long histories of bleakness and ancient legends of rain; while on the high darkening land far off behind him he saw lights begin to blink where the houses were. He walked with the gravity and the solemn air of one who has important business with men; yet his back was turned to their houses and he went where no man wandered, travelling towards no hamlet or lonely cottage of man, for the marsh ran right into Elfland. Between him and the nebulous border that divides Earth from Elfland there was no man whatever, and yet the traveller walked on as one that has a grave errand. With every venerable step that he took bright mosses shook and the marsh seemed about to engulf him, while his worthy staff sank deep into slime, giving him no support; and yet the traveller seemed only to care for the solemnity of his pacing. Thus he went on over the deadly marsh with a deportment suitable to the slow procession when the elders open the market on special days, and the gravest blesses the bargaining, and all the farmers come to the booths and barter.