Originially called "Iowa Circle", Logan Circle is located six blocks east of DuPont Circle. At the center of the circle is a monument to Major General John Logan a Union commander in the War Between the States, who distinguished himself at both Vicksburg and Atlanta. In 1930 Congress renamed the circle in honor of Logan who was also a U.S. senator.

It marks Sphere number Two, and is depicted in the map like a Vesica Pisces, composed of two overlapping circles.