English: Detail of an Ionic capital atop a column on the dais of the Old Amphitheater in Section 26 of Arlington National Cemetery in Arlington, Virginia, in the United States.

In order to accommodate the need for a large meeting space at the cemetery, U.S. Army Quartermaster General Montgomery C. Meigs (superintendent of the cemetery) built an amphitheater. The structure was built southwest of Arlington House (the home of Robert E. Lee). A one-room schoolhouse Lee had built was torn down and the amphitheater constructed on the site in 1874. The amphitheater is an oval whose interior measures roughly 90 feet across and 60 feet deep, and circumscribes a shallow natural bowl in the earth. Its axis is roughly southwest to northeast, in a line with the Civil War Unknowns Memorial and the center of the Arlington House flower garden. The rectangular dais is about 25 feet deep and 50 feet across, and raised about 3 feet. The dais is built of brick, with square columns at each corner. The surface of the dais is dark grey rectangular granite slabs. The columns supporting the trellis overhead are wood painted white. Each is topped with an Ionic capital. In the center of the dais, at the front, is a rectangular grey granite slab. On this slab sits "the Rostrum," a Neoclassical, three-foot-high podium. Upright scrollwork pedestals adorn the corners of the left and right faces. Between the scrollwork pedestals is a small shield encircled by a wreath. On the front of the Rostrum, in raised lettering, is the motto of the United States: "E Pluribus UNUM." Sprigs of holly and rosettes are on either side of the motto.

The exterior of the amphitheater is a colonnade covered by an overhead trellis approximately 25 feet wide. The trellis is constructed of upright wooden 2 x 6 inch planks. The trellis is supported by square brick columns painted white, approximately 2 feet on each side. Each sits on a slightly larger square brick base, and is topped by a wooden Doric capital. Low boxwood hedges line the interior side of the walkway beneath the trellis. The exterior side of the walkway is planted with flowers and flowering shurbs. The walkway itself is made of dark grey rectangular granite slabs set in the earth. American wisteria vines covered the trellis as of 2011 (although these have been removed at various times in the past to examine and permit conservation of the trellis).

The Old Amphitheater can sit 1,500 people tightly on wooden folding chairs. As of 2011, the amphitheater bowl is lined with grass.