Railroad officials in the early 1900s sought to spare travelers the sight of Roman soldiers’ private parts.

At night, a grove of towering redwood trees growing through the pavement block out all light from the so-called “Dark Park” of Madrone Avenue.

The last orange grove of the San Fernando Valley is owned and protected by CSU Northridge.

This “living museum” at UCLA exhibits thousands of plant species from all over the world.

An astounding collection of medical specimens, including bits of President Lincoln.

The word "Watergate" will forever be associated with the infamous scandal in 1972, but this fountain is famous in its own right.

One of the first Second Empire-style buildings constructed in North America.

The former home of the woman who successfully fought to integrate restaurants in Washington, D.C.

Depending on who you ask, this controversial treehouse is either a charmingly creative child's playhouse or an illegal encroachment on public land.

An easily overlooked memorial to a Ukrainian famine-genocide that killed over 4 million people.

An overlooked oasis of quiet on the grounds of Washington's monumental basilica.

A clone of a cloned tree that was so important it allegedly had its own guards.

Four bald cypress trees in Lafayette Square, across from the White House, mark the southern edge of a 100,000 year old cypress swamp.

The span is crooked and made from two older recycled bridges.

The most accurate timepiece in the world.

Housing the National Women's Party since 1929, this historic house is now a monument to the fight for gender equality.

Decades before the scandal, this staircase on the river was a literal "water gate."

You could be standing at the site of one of D.C.'s most fatal tragedies and not even know it.

A brass plaque dedicated to a convicted cannibal hangs in the National Press Club, and that's not even the craziest part of the story.

These recently uncovered walls are all that's left of Washington, D.C's first defense contractor.

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

A hoard of sky catalogs, astrophysical journals, even the works of Galileo and Copernicus.

A celebrity from the late Cretaceous period.

A computer bug so primitive it was an actual insect.