This covered bridge was used by both Union and Confederate troops during the Battle of Gettysburg in 1863.

The Lincoln Memorial has inspired many, even though a word on the inscription appears to be spelled incorrectly.

Look closely and you’ll notice that the color changes a third of the way up the tower.

This large garden vase urn has nothing to do with the seventh U.S. President—it was designed by one landscape designer to honor another landscape designer's contributions to the National Mall.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

The story behind this beloved toy—named for Theodore Roosevelt and owned by his grandson—is more complicated than you might guess.

Built for an exposition in 1915, these horticultural displays have stood the test of time.

A blast from the past in central San Diego.

Go deep on these fascinating fish, and get a bonus lesson on the importance of marine conservation.

The world’s oldest active sailing ship.

Outstanding taxidermy dioramas showcase the grandeur of the continent's wildlife with spooky realism.

Creating this diorama spurred naturalist Carl Akeley to begin advocating to protect the apes.

This magnificent herd of stampeding elephants has been frozen in time for over a century.

It’s not hard to see why the historic Peabody Conservatory of Music’s library has been described as a “cathedral of books.”

The design of this historic domed church was influenced by Thomas Jefferson and intended as a statement of religious freedom.

Baltimore's classic clock tower was once topped by a rotating, 20-ton medicine bottle.

A museum dedicated to the history & joys of the trail & your best chance to see hikers throwing up ice cream.

A labor of love built by local hang-gliding enthusiasts, this ideal launch spot was outlawed by the authorities and has since been largely abandoned.

Time travel with sweets across history at this research-based candy store.

This advertisement for talcum powder was painted on the rock face and has since defied removal.

These unusual rooms on wheels are holdovers from the 1960s.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

A backdoor to Machu Picchu that only the most foolhardy infiltrator would attempt to breach.