Innisfree is a small, uninhabited island situated in the northern part of County Sligo, Ireland. It is surrounded by the waters of Lough Gill, hence the term in the title, “lake isle.” Ireland itself is also completely surrounded by water, with the Atlantic to its west, the Irish Sea separating it from England, and the Celtic Sea to its south. Innisfree, therefore, by similarity of locale, serves as a symbol for Ireland itself. The desire the speaker feels to reside on Innisfree can be looked at as their desire to return to Ireland, or in Yeats’s particular case, his Irish roots. Rejecting the polluted and overcrowded London for Innisfree, the speaker believes, would allow a return to the mythic and natural world to which the speaker truly belongs. Innisfree—and Ireland—are both connected to the “deep heart’s core” (Line 12). The heart is an echo as well of a beloved island since it is metaphorically surrounded by the rest of the body, which it pumps life into.

The common linnet is a small bird similar to a house finch. Its name derives from its tendency to eat flax, which in Latin is called linum. It is common to the United Kingdom and large flocks may form while breeding, which usually happens along shorelines—this may account for Yeats’s description of the bird along Innisfree.