Seventeen square miles. Seventeen (or so) residents. 100% Kentucky. And isolated from the rest of the state. Welcome to Kentucky Bend.
Kentucky Bend is in the southwest corner of the state, but is entirely surrounded by two other states. To the south is Tennessee, which you can see in the map above. Looping around the area, forming the west-to-east borders, is the Mississippi River. Across the river? Missouri. One cannot get from Kentucky Bend to the rest of Kentucky without crossing into another state first.
The carve-out was caused accidentally. When the states drew their borders, the powers that be agreed that the Kentucky border would extend “as far west as the bank of the Mississippi [River] opposite the westernmost bank of the Mississippi [River] in Missouri” per one amateur historian. But no one realized that a bend in the river (an “oxbow loop meander”), given that border, would lead to this ridiculous result. Until the mid-1800s, Tennessee claimed Kentucky Bend (under a different name, naturally) as its own, finally dropping the cause in around 1848.
Nevertheless, the mailing address for the area? Tiptonville, Tennessee.
Related: “When the Mississippi Ran Backwards : Empire, Intrigue, Murder, and the New Madrid Earthquake” by Jay Feldman. Four stars on 32 reviews.