The National Mall is often called “America’s front yard,” but did you know it also used to be America’s toilet? In the 1800s, a canal that ran along what’s now Constitution Avenue was “the grand receptacle of nearly all the filth of this city,” and emitted “70 distinct stinks,” according to the historical writings of two observers at the time.

The number of distinct stinks on the Mall is just a fraction of that today, but they are still out there. Trust me, I know. Over the past few months, I visited every single public women’s room on the Mall — 59 restrooms in total. That includes facilities from the Supreme Court and Capitol Visitor Center on the east end of the Mall to the freestanding National Park Service kiosks on the west side, and bathrooms at all of the (currently open) museums and monuments in between.

To my surprise, I found a veritable paradise for the pee-shy. If you’re willing to poke around the basements and forgotten corners of the less popular Smithsonians, you can find secret bathrooms that are as deserted as government offices after rumors of snow.

What you will not find are so-called feminine products. Of the 36 tampon machines I found on the National Mall, only seven delivered the goods. Most of the rest ate my quarters. Is this evidence of a conspiracy to steal change from desperate women, one that goes all the way to the very highest levels of our federal government? All I can say is that if men needed tampons, they would be readily available in all bathrooms, and they would be free.

The restrooms of the National Mall may seem to be a trivial matter, especially when compared to the notable buildings and historical treasures that surround them. But if I’ve learned anything from my expedition, it’s that some bathrooms are worth going out of your way for. To quote a tourist from Fort Collins, Colo., who was impressed with the National Gallery of Art’s broad toilet seats, “I’d walk a long distance to park my cookies there.”

Here are reviews of 10 noteworthy facilities I found on my travels, followed by an interactive map with reviews and photos of all 59.

Best for slapstick comedy
Constitution Gardens

Near 20th Street and Constitution Avenue NW
This freestanding kiosk harbors at least two species of spiders and emits a mildewy smell reminiscent of summer camp. One stall door lacks locks but instead offers an innovative “swing through” feature, which allows people to push the door into you while you’re using the toilet. This feature also allows you to whack unsuspecting bathroom patrons with the door on your way out.
Library of Congress Thomas Jefferson Building

10 First St. SE
With marble walls, golden garbage cans and handsome cherry cabinetry, the Library of Congress’ bathroom on the lowest level invites you to poop like a turn-of-the-20th-century railroad tycoon. Babies may also enjoy the building’s belle epoque opulence, as this bathroom features a freestanding, sleigh-style changing table — no cheap plastic wall-mounted tables for your little scion of industry. On your way out, be sure to check out the library’s collection of area phone books from the early 2000s.
National Museum of the American Indian 

Fourth Street and Independence Avenue SW
Be warned: While all four bathrooms in this museum have paper towel dispensers, not one of them actually dispenses paper towels. Instead, they dispense shame: “Help reduce paper waste and conserve natural resources,” read laminated signs that urge you to use the hand dryers. A word of advice: Skip the smelly, busy bathroom on the first floor and go to the second-floor bathroom instead. In addition to being quiet and roomy, the bathroom has lots of comfy seating nearby.
National Museum of African American History and Culture 

1400 Constitution Ave. NW
Why wait 30 minutes in the first-floor bathroom line when you can have two huge bathrooms on the basement levels nearly all to yourself? Actually, those bathrooms are probably empty because there’s a 20-minute wait to get to that part of the museum. Your best bet might be the second- or third-floor restrooms, which have nearby benches with a nice view of the Mall. But plan ahead: All five of the tampon machines in this less-than-a-year-old museum failed to deliver.
Most communal
Lincoln Memorial 

2 Lincoln Memorial Circle NW
You’ll pass a lovely watercolor of the Lincoln Memorial and listen to patriotic music emanating from the nearby exhibits on your way to this busy bathroom. Once inside, your heart will be warmed as you see people from many nations bridging cultural divides and bathroom partitions, as they pass scarce toilet paper from stall to stall.
Best for the pee-shy
National Museum of African Art 

950 Independence Ave. SW
If you’re looking for privacy, you’ll love the bathrooms at one of the Mall’s least visited museums. Here, you can do your business in solitude, accompanied only by the thrum of an aging HVAC system. On the lowest level, you’ll find a machine that promises, but does not deliver, tampons for 10 cents each.
Best antiquities
National Museum of Natural History 

10th Street and Constitution Avenue NW
This museum has a vast collection of relics from ancient civilizations, including mummies from Egypt, colossal stone statues from Easter Island, and hand dryers with roughly the same blowing power as a ladybug’s sneeze. You’ll find two of the oldest hand dryer specimens — one held together with duct tape — in a sunny, peach-tiled bathroom near the “African Voices” exhibit.
Thomas Jefferson Memorial 

701 E. Basin Drive SW
This bathroom, with its black-and-white-tiled floor, is more reminiscent of “Twin Peaks” than of Monticello — especially since one of the toilets was covered in a big plastic bag like a homicide victim. You’ll find this sort-of-air-conditioned bathroom on the ground floor, near the gift shops.
National Gallery of Art, East Building 

Fourth Street and Constitution Ave. NW
The National Gallery of Art’s East Building was designed by I.M. Pei, who used geometrical motifs to inform his design throughout the space. In the belowground bathroom, for instance, you’ll find isosceles triangle tiles, which complement the overall trapezoidal shape of the building. But it’s not all pointy angles down there: Curvy door handles provide a pleasing counterbalance to the building’s sharp lines. They also cut down on bathroom traffic. At least one group of tourists, after failing to figure out whether to push or pull the door open to get inside, incorrectly concluded it was locked.
Best overall

Smithsonian Castle
1000 Jefferson Drive SW
This Smithsonian building doesn’t have much by way of exhibits, but it makes up for that with its palatial public bathroom. An antechamber dappled with natural light leads to a grand, white-tiled bathroom with black and red accents. Adding to the overall sense of avuncular civility is a faux-leather bench where Smithsonian scientists probably gather to discuss their research findings. And, in addition to a Purell dispenser and toilet seat covers, this bathroom offers the very rarest of amenities: a working tampon machine.