1. Seek out Lincoln's Summer Cottage
Abe diehards can make the trek to Lincoln's Cottage (lincolncottage.org) in northern DC. The 16th president came here to beat the heat and jot notes for the Emancipation Proclamation in leafy seclusion. Ghosts float on the veranda's breeze. Tours of the home tell the tale.
2. Gape at the view from the Library of Congress
The world's largest library lets you check out more than a Gutenberg Bible and the dusty books of Thomas Jefferson. Head to the James Madison Memorial Building's covert 6th-floor cafeteria, trimmed with floor-to-ceiling windows, and you also get sprawling vistas over DC's river-sliced landscape.
3. Learn your state tree at the National Arboretum
Take a walk in the woods past meadows, glades and an otherworldly garden studded with Corinthian pillars that were once a part of the Capitol building. The State Tree Grove adds to the grooviness at the National Arboretum, sprouting everything from New York's sugar maple to California's giant sequoia.
4. Ogle brains and hairballs at the National Museum of Health and Medicine
Macabre exhibits galore pack this Department of Defense-run museum. The stomach-shaped hairball leaves a lasting impression (a 12-year-old girl ate THAT?), as does the megacolon (use your imagination). The showpiece is the bullet that killed Abraham Lincoln, encased alongside bits of his skull.
5. Get buzzed at Gravelly Point Park
Prepare for wild plane spotting at the grassy patch beside Reagan National Airport. The earth shakes and roaring engines deafen as jetliners zoom stunningly close overhead, en route to the runway a few hundred feet away. Intrepid plane-spotters walk from the airport but it's safer to drive or take a taxi.
6. Delve into the crypt at Washington National Cathedral
Gargoyles shaped like Darth Vader and moon rocks embedded in stained glass windows are your first hints that Washington National Cathedral is not your average house of worship. The crypt containing Woodrow Wilson’s marble tomb and Helen Keller’s ashes confirm it.
7. Peruse art up-close at the Phillips Collection
It tends to get lost in DC's museum bounty, but the Phillips Collection is the nation's oldest modern art museum, filled with famous pieces by Renoir, Gauguin and other modern icons. The intimate galleries, set in a restored Dupont Circle mansion, put you uncommonly close to the artworks.
8. Wander the woods of Theodore Roosevelt Island
The mustachioed 26th president, an avid conservationist, would adore his namesake wilderness preserve. The car- and bike-free isle floats in the Potomac River, offering birds, trails and tranquility via a footbridge from the mainland.
9. Live the mansion lifestyle at Anderson House
There aren't many Embassy Row mansions that invite you inside to gawp at their gilded ballrooms, tapestries and sparkling chandeliers. Fewer still let you in for free. Anderson House does. It's the headquarters of the Society of the Cincinnati, an age-old patriotic group.
10. Examine the DEA's bong collection
The Drug Enforcement Administration (DEA) operates a small museum in its lobby, where exhibits on psychedelics and videos with titles like One Sniff Can Kill supplement a whopping display of bongs and pipes.
11. Join the dogs at the Congressional Cemetery
Yes, that is a dachshund snuffling around J Edgar Hoover's tombstone, while a black lab lopes over the final resting place of composer John Philip Sousa. That's because the Congressional Cemetery (congressionalcemetery.org) – a burial ground of famous Washingtonians since 1807 – doubles as a members-only dog park.
12. Follow the graffiti to The Fridge
The Fridge (thefridgedc.com) is a friendly gallery in Capitol Hill that specializes in street art. Part of the fun is finding it. Follow the murals and graffiti into the alley beside the oyster shop on 8th St SE, and voila: public art in all its funky glory.
13. Pay your respects at James Smithson's tomb
The guy who founded the Smithsonian Institution catches his eternal zzz's in the Smithsonian Castle. Pay homage at the eccentric Englishman's crypt, and thank him for his $508,318 bequest in 1826 that morphed into 19 forever-free museums.
14. Behold the Peacock Room's opulence
It hides in a corner of the Freer Gallery at the Museums of Asian Art, shimmering in hues as iridescent as the bird it's named after. James McNeill Whistler designed the blue-and-gold room to set off the 250 sumptuous, Far Eastern ceramics on display.
15. Uncover the story behind George Mason's memorial
He's the statesman who wrote the Bill of Rights prototype, and his memorial is a refuge of flowers and fountains amid the National Mall mania. Take a seat next to Mason's statue, and soak up his wise words on human rights.
16. Pretend you're in Russia at the Hillwood Museum & Gardens
Cereal heiress Marjorie Post was living in the USSR in the 1930s when the Soviets were selling off Czarist swag. She bought up loads of furniture, paintings and Fabergé eggs, which now fill her shockingly gorgeous Hillwood estate.
17. Get the Embassy Row gossip at Woodrow Wilson House
While docents are happy to show you the house where Woodrow Wilson lived after his presidency – a genteel 1920s manor of European bronzes, exquisite china and Mrs W's flapper dresses – the real fun is hearing them dish on the neighborhood's current rich eccentrics and ambassadors.
18. Ascend the Spanish Steps
You're walking up 22nd St to S St NW, and suddenly an enchanting staircase appears. The Spanish Steps, as they're known, were modeled on those in Rome's Piazza di Spagna. Climb up for an atmospheric view of Embassy Row.
19. Sniff out the 'corpse flower' at the Botanic Garden
The United States Botanic Garden is the National Mall's overlooked gem. Roam past roses, orchids and ferns, then seek out the Amorphophallus titanum, a flower whose name translates to 'giant misshapen penis' and whose erratic blooms smell like rotting flesh. Yeah, baby!
20. Discover DC's most awkward memorial in Lincoln Park
The joggers and stroller-pushing families in Lincoln Park zip right passed the Emancipation Memorial, a statue of a chained slave kneeling at Abe Lincoln's feet. Freed black slaves raised the funds to erect it in 1876, but the slave's supplicant position makes it DC's most bizarrely uncomfortable monument.