http://en.wikipedia.org/wiki/Grant%27s_tomb
Grant's Tomb is a mausoleum containing the bodies of Ulysses S. Grant (1822-1885), an American Civil War General and the 18th President of the United States, and his wife, Julia Dent Grant (1826-1902). The tomb complex is now officially known as the General Grant National Memorial and is located in Riverside Park in Manhattan, New York, New York, near the intersection of Riverside Drive and 122nd Street.
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A riddle relating to Grant's Tomb, popularized by Groucho Marx on his game show You Bet Your Life, is "Who is buried in Grant's Tomb?" Though the proper answer is "nobody"—Grant and his wife are entombed, not buried—Groucho would usually accept "Grant".
Yes, I'm a smart a$$ :)