The Ellipse

The Ellipse, sometimes referred to as President's Park South, is a 52-acre park south of the White House fence and north of Constitution Avenue and the National Mall in Washington, D.C., US. The Ellipse is also the name of the five-furlong circumference street within the park. The entire park, which features monuments, is open to the public and is part of President's Park. The Ellipse is the location for many annual events.

From a mathematical point of view, the Ellipse is truly an ellipse. Its dimensions are 1,058 feet for its major axis and 903 feet for its minor axis. Its eccentricity computes as e = 0.52 and its foci are 552 feet apart, each 276 feet from the center of the ellipse.

Source: Wikipedia