These caves secretly held national treasures during World War II.

After a catastrophic forest fire, a Greek artist transformed scorched tree trunks outside an old sanatorium into this haunting sculpture garden.

The oldest standing Byzantine church in Athens is tucked within a monastery in the middle of an upscale shopping district.

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

The ruined doorway is a portal to the building's turbulent and torturous past.

This small 16th-century church in Athens is almost entirely surrounded by a modern building.

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

Savor sheep milk yogurt at the last of Athens' dairy bars.

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

This mystical orb covered in strange symbols is thought to have been used in ancient Greek magical rituals.

The Cycladic architecture makes this Athens neighborhood feel like an island paradise hidden in the shadow of the Acropolis.

The railway carts travelers to central Athens's highest peak, which offers stunning vistas of the city.

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

This twice-relocated "Usonian" home is among the smallest built by master architect Frank Lloyd Wright.

Rowdy rebels fortified this home during the first popular uprising in United States history.

The Grand Ole Opry's big voice came from a small home in rural Virginia where she was eventually buried.

Bubbling up from deep underground is the warm crystal clear water that fills the Warm Springs Pools, America's oldest spa.

An entire subdivision was accidentally built on a flood plain, resulting in its eventual demolition—but the streets are still there.

Austin’s local mountain isn’t really a mountain at all.

This stone windmill marks an old, mysterious homestead in what is now central Austin.

This simple frog painting created by musician Daniel Johnston embodies the spirit of Austin.

This eclectic Austin curiosity shop is home to all things strange and unusual.

A view-altering observatory at the University of Texas.

A grove of colossal man-made flowers built to collect the sun's rays.