WASHINGTON (CNN) -

Ordinarily, I'm not a fan of vandalism.

But years ago I spotted some graffiti in Washington that struck a chord. Someone had spray painted the symbol for anarchy -- a circled "A" -- on a Chinatown grocery store.

And I wondered: Did they know?

Did they know that that building, a century earlier, had been Mary Surratt's boarding house? Did they know that conspirators had gathered there to plot the kidnapping and assassination of an American president? Did they know that the site had played a role in the biggest act of anarchy in this country's history?

Was the graffiti just accidentally appropriate? Or could punks with paint be profound?

I don't know the answer, of course. But I know that this city is teeming with people who, like me, relish its hidden history.

Washington is a town of majestic monuments and memorials. And those are worth visiting. But if you limit your sightseeing to the obvious -- if you ignore the obscure -- you'll miss the good stuff.

That is what I had in mind when I asked historians and history buffs to show me places -- off the beaten path -- that have stirred their love of history and this great town.

WASHINGTON COLISEUM: "I Saw Them Standing There"

Four boys, in dire need of haircuts, come to town, looking to conquer it.

The British tried it once before, in 1814. Burned the city. It left a bad taste in everyone's mouth.

But this time, they try soft diplomacy. A little twist and shout. A little ditty about wanting to hold your hand.

And it works.

Improbable as it sounds, it happened in a barrel-shaped architectural ruin just north of the Capitol on 3rd Street NE.

Shortly after 8:30 p.m. on Feb. 11, 1964 -- two days after appearing on "The Ed Sullivan Show" -- the Beatles took the stage in Washington Coliseum. It was the Beatles' very first stage concert in the United States.

Critics later say the concert is as singular moment in rock history -- a moment when the early Beatles seemed even more joyous than their shrieking teen-age fans.

Richard Layman, who fought to preserve the Coliseum, cherishes this place for many reasons. Built in 1940 and 1941, the building served as an ice rink, sports arena, worship hall, trash transfer station and parking garage. Nation of Islam leaders Malcolm X and Elijah Muhammed spoke here. It hosted numerous professional sports teams, and was home to the Ice Capades.

For Beatle devotees, this is a shrine.

They still have ticket stubs, and remember whether they paid $2, $3 or $4. They gush about how Paul smiled at them.

An age of innocence? Not exactly. The Russians threatened us from outer space. The pains of segregation and integration were rocking the country. And, just three months earlier, an assassin felled the leader of the free world.

But for about 35 minutes on a cold February night in 1964, four boys from Liverpool entered a converted ice rink and warmed a generation's heart.

COURTROOM DRAMA: Last act of the Civil War

The man, a tavern owner, took the witness stand.

"I was acquainted with John Wilkes Booth," he said. "Booth came into my restaurant [adjoining Ford's Theater] on the evening of the 14th of April."

Booth "walked up to the bar, and called for some whiskey, which I gave him; he called for some water, which I also gave him; he placed the money on the counter and went out. I saw him go out of the bar alone, as near as I can judge, from eight to ten minutes before I heard the cry that the President was assassinated."

Peter Taltavul spoke those words, in this room, just one month after Lincoln died.

By then, authorities had already tracked down Booth, cornered him, and killed him. And they had rounded up eight people who they believe had assisted him.

They convened a military commission to conduct the trial in the third floor of what was then a federal penitentiary. The co-conspirators, they reasoned, were not "civilians," but were "enemy belligerents." The nation was seeking justice and vengeance, and it would come swiftly.

On July 6, 1865 -- less than three months after the assassination -- the commission found all eight conspirators guilty. It sentenced four to hang, and four to prison terms. The condemned were hanged the next day.

A year later, the Supreme Court would rule that a defendant could not be tried by military commission when civilian courts were functioning. But it was too late.

The penitentiary is now closed and largely demolished. The land is part of Fort McNair at the southernmost point of Washington.

Visitors -- mostly lawyers and Civil War buffs -- are frequently overwhelmed when they enter the room, said Susan Lemke, a special collections librarian who has accumulated artifacts related to the trial. "There's no substitution for actually witnessing or being in the middle of a historic site like that," she said.

THE GALLOWS: Where generals "serve," conspirators hanged

Michael Kauffman is struck by the incongruity of it all.

On the edge of a Fort McNair tennis court, where generals now casually toss their gym bags, Abraham Lincoln's death was avenged.

Here in this spot, near the penitentiary room where the sentences were handed down, on a miserably hot day in July 1865, Union Army Capt. Christian Rath raised his hands and clapped three times. On the third clap, soldiers knocked supports out from under a gallows, and four prisoners fell. Their bodies jerked violently at the ends of their ropes. The prisoner in the dress appeared to die instantly. But one of her three accused accomplices writhed for five minutes before surrendering his ghost.

"I am one of those people who think that if you really want to understand history, you have to go to where it happened," says Kauffman, an expert on the Lincoln assassination.

So Kauffman leads me to this empty tennis court. It is drizzly and cold, and there is little here to evince the images and emotions of that hot July day. The penitentiary's tall wall has been demolished, and a building prominent in photos of the hanging has been altered almost beyond recognition.

Almost.

Kauffman shows me the place where the wall met the building. And in my mind's eye, the gallows fall into place.