Dealey Plaza is a depression. It is a shallow basin on the western edge of downtown, framed by concrete structures called pergolas and peristyles that were built in the late 1930s by the Works Progress Administration. Designed as a gateway to the city, the plaza is more of an ode to the automobile because the broad lawn is sliced by three converging streets: Elm, Main and Commerce. They slope from east to west and meet beneath a rail line in what is known as the triple underpass.

That is where President and Mrs. Kennedy were headed, on Elm, when the ghastly thing happened.

On the north side of the plaza is the famous grassy knoll, where the second shooter supposedly lurked. There is a second grassy knoll on the south side of the plaza. And the grassy knolls aren't actually knolls, but rather are just slopes on the rim of the plaza.