"The Lake Isle of Innisfree" by Yeats is a ballade-like poem. Each stanza has three lines in hexamater with a caesura after the third foot and a fourth line in tetrameter. The rhyme scheme is ABAB for each stanza.
The most pithy summary of the poem is that the speaker imagines a bucolic existence on an uninhabited island (Innisfree). It is his place of loneliness, which he thinks of as he stands in the middle of a city.