A WWII concrete octagon hiding in an Indiana cornfield
In the fall of 1943 the Navy poured an octagonal concrete mat, 1,800 feet across, in the fields a mile west of Converse: an all-way landing surface for training Bunker Hill's naval aviators, one of 26 satellite fields ringing the station, built so a cadet could land in any direction and never meet a crosswind. The Navy spent nearly half a million wartime dollars on concrete for land it never owned; when the war ended it walked away, and the town of Converse took the field over in 1947. The octagon still operates as a public airport, and the shape is unmistakable from the air.