The story
From pleasure + dome, from the opening lines of Kubla Khan (completed 1797; published 1816) by Samuel Taylor Coleridge: "In Xanadu did Kubla Khan / A stately pleasure-dome decree: / Where Alph, the sacred river, ran / Through caverns measureless to man / Down to a sunless sea."
Etymology from Wiktionary, CC BY-SA 4.0.