JFK's Eternal Flame and Grave
Arlington, Virginia
The eternal flame at the burial site of John F. Kennedy was First Lady Jackie's idea, supposedly inspired by a similar grave flame that she'd seen in fashionable Paris. She lit the flame herself, with a gas-soaked rag on a stick, at the conclusion of JFK's burial. It was engineered literally overnight from a tiki torch, and for years it remained a relatively crude mound disguising a gas pipe. Millions of mourners and tourists paid their respects at what became a focal point of Arlington National Cemetery.
The grave site was finally upgraded in 1967, and that eternal flame burned until 1998, when it was retired to the National Museum of Funeral History, where it's displayed with a flickering candle bulb. The replacement flame was itself replaced in 2013.
Despite its "eternal" reputation the flame has gone out from time to time, but never for very long.