Like many of Dunsany's early works, "Idle Days on the Yann" is set in a dreamworld where the descriptions recall Arabia, Greece, North Africa and India.

In his autobiography Patches of Sunlight (1938), Dunsany explained the background to this setting as a combination of Biblical readings, an interest in Greco-Roman antiquity, having briefly seen Tangier at the turn of the century, stories about Egypt his father had told him, the impact of Rudyard Kipling's fiction at a young age, and experiences from South Africa during the Second Boer War.

The protagonist is impressed by Perdóndaris, but discovers a huge ivory gate made of one solid piece, and returns to the ship terrified.

The ship finally reaches the Gate of Yann: two narrow, mountain-high, smooth and pink marble cliffs that the river flows between into the sea.

[3] The surface plot of H. P. Lovecraft's 1919 short story "The White Ship" is modeled on "Idle Days on the Yann".

[5] Further, Robert M. Price has argued that the name of Lovecraft's fictional deity Shub-Niggurath is likely to have been inspired by Sheol Nugganoth in Dunsany's story.