East Potomac Miniature Golf on Hains Point, opened in 1931, is one of the oldest continuously operating mini-golf courses in the United States. Breanna Coleman, left, and Matthew Desjardin played the course on a recent evening. (Michael S. Williamson/The Washington Post)

Soapstone Market doesn’t appear in “111 Places in Washington That You Must Not Miss,” but Andréa Seiger treats the grocery as if it were No. 112. Waiting to place her order, she points out several noteworthy features of the Van Ness refueling station. The nearly two-year-old spot, she explains, is owned by neighborhood boosters John Fielding and Tracy Stannard, who also run Broad Branch Market in the Chevy Chase neighborhood. And the coffee, she reveals, is roasted locally, in Northeast Washington (Zeke’s) and Alexandria (Swing’s).

Seiger, 55, is not a D.C. native, though after years in the tourist industry, she speaks with the authority of one. Which made the native Ohioan, who moved to the capital after college, an ideal choice to author the Washington edition of the “111 Places” guidebook series, released in June by German publisher Emons Verlag. “One hundred was too conventional and 110 was too round,” she offers in explanation of the seemingly arbitrary number of stops. As it happens, 11 is a lucky number in Cologne, home of the publishing house, so 111 it was.

Her guiding principle for the project was: “Let’s do the hidden in plain sight.” In the early stages, Seiger listed about 300 attractions, which she compiled through a combination of research, touring, happy accident — and even personal recollection. Take No. 44, Gorby Intersection, a street corner with no historical marker, just memories of the moment — which Seiger witnessed with her sister and mother — when then-Soviet leader Mikhail Gorbachev left his motorcade car to shake excited onlookers’ hands. “We could see Gorbachev and the KGB,” she recalls. “And then they shoved him back into the car, and everyone went to lunch.”

On a steamy late summer day, there isn’t time to reprise all 111 sites in Seiger’s book, so we settle on seven highlights. At Freedom Plaza downtown, Seiger rubs her sneaker over the inscription marking the site of the Martin Luther King Jr. time capsule. “No one has any idea that they are literally walking on this man’s history,” she says, as several pedestrians stroll obliviously by. The container was buried on Jan. 12, 1988, and won’t see daylight till 2088. If you’re unsure of your plans for 70 years from now, here’s a preview of what’s inside: the reverend’s robe and Bible, photos, sermons, a mini Liberty Bell and a recording of his “I Have a Dream” speech, which he completed across the street at the Willard hotel bar.

Over at the U.S. Department of Transportation, we visit the Transportation Walk, an “outdoor museum” that encircles the building. Spanning seven blocks and four time periods, it highlights such important developments as the ship wheel, the Wright brothers’ 1903 Flyer, and Eisenhower’s National Interstate and Defense Highways Act.

Nearby, at the National Museum of the U.S. Navy, the whale-size Bathyscaphe Trieste makes Seiger look the size of a fish-tank figurine. In 1960, the son of inventor Auguste Piccard boarded the diving vessel to descend 35,814 feet into the Challenger Deep, part of the Mariana Trench. More than a half-century later, “Titanic” director James Cameron attempted a similar dive, but fell 27 feet short. “Who’d-a thunk that you could counter-engineer a hot-air balloon into a submersible?” Seiger muses of Piccard, who first tinkered with flight balloons.

Before leaving the military compound, we swing past a parking garage built on the former site of a foundry that once purportedly housed the leg of Col. Ulric Dahlgren. A plaque on the wall indicates that the limb the Union soldier lost after the Battle of Gettysburg resides within, but another sign above the plaque maintains that it’s not there. Only the leg knows where it rests.


English scientist and Smithsonian Institution benefactor James Smithson is entombed in the Smithsonian Castle. (Michael S. Williamson/The Washington Post)

No controversy disturbs the body of James Smithson, the English scientist entombed in the Smithsonian Castle. In his will, the bachelor bequeathed his estate — $508,318 in 1838, or more than $13 million today — to the creation of an educational center in the United States. After Alexander Graham Bell and his wife retrieved Smithson’s remains from an Italian cemetery, the Smithsonian placed his marble crypt near the Mall-side entrance. Seiger points out the nature-themed engravings, including a moth that symbolizes new life after death.

The Grim Reaper wags his head again at the book’s stop No. 13 (coincidence?). Seiger had to fight to include the Bladensburg Dueling Grounds, which lies a few blocks over the District line in Colmar Manor, Md. “There were more than 50 duels here, involving a lawyer’s son, an inventor, admirals and congressmen,” she says. The men fought over such trifling issues as the speed of a steamboat.

Finally, No. 78: the miniature golf course in East Potomac Park. Opened in 1931, it’s one of the oldest continually operating mini-golf courses in the country, yet — like the six other places we visited — I’d never heard of it during my 21 years in Washington. Which reinforces a fact that every self-respecting Washingtonian knows, or should know: This city is more than grand monuments and is full of small surprises — often hidden, as Seiger anticipated, in plain sight.

Andrea Sachs is a Washington Post staff writer.