A spectacular tribute to statesman and philanthropist Andrew Mellon.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

The National Park Service’s best-kept secret with views that rival any in D.C.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

This simple convenience store sits on the location where the Ouija board was named—and has a plaque to prove it.

One artist’s scheme to expand museum viewing hours into the evening led to the illumination of an entire city.

The trials and tribulations of marking Poe’s grave.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

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

Known as the "Cross At The Crossroads," this massive metal cross is just short enough to avoid the FAA.

A sharply wedged sundial marks the point at which each day in the United States begins.

The oldest cemetery of modern-day Athens blends the modern and ancient worlds.

A 400-foot-tall tall map of Chicago makes this once-ignored building stand out.

Half-sized replica of the Leaning Tower of Pisa built to honor Galileo.

This gem is often wrongly overshadowed by the larger, newer Metropolis church in Athens.

An ancient octagonal weather station named for the eight Greek gods of wind.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

Legend says this sacred tree was a gift from goddess Athena.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The only mill in the state that features a covered bridge.

The show pony of cave systems, Fantastic Caverns manages to live up to its name.

With 3,000 bikes on display, the world's largest bicycle museum includes some famous rarities.