The heads and relics of 179 monks slaughtered by pirates are on display within this Ceonobic Monastery.

These artifacts were discovered during the construction of the airport, with some dating back to the Neolithic period.

This beehive tomb built for royalty sat hidden for over 3,000 years.

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

Gladiators once walked this ancient, subterranean passage.

View the ancient remains of buildings and the ancient "River of Hades" before hopping on a train.

The ruins of this ancient fortification wall sit in the middle of a quiet, residential intersection.

Tear apart fatty, gently charred lamb chops with your bare hands.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

The site where hundreds of Greeks were tortured by the Nazi secret police is now a cosmetics store.

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.

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

A former military hospital is now used to study and preserve artifacts of the Acropolis.

These caves secretly held national treasures during World War II.

A Byzantine-era church hidden in a wooded area below the Acropolis.

Marta Becket's hand-painted theater in the desert.

An architect's childhood fantasy treehouse made real.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

A beautiful geyser under environmental threat.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

This Yellowstone geyser may not shoot as high as the nearby Old Faithful, but it erupts for considerably longer.

The only natural lake in the world that drains into both the Atlantic and Pacific Oceans.

In one of the hottest parts of the Mojave Desert, shallow bedrock forces the typically dry Mojave River to the surface in this canyon, providing a vital oasis for humans and wildlife.