This singular Irish dolmen is more Frank Lloyd Wright than upright stonehenge.

One of Ireland's most infamous prisons for rebels including men, women and children.

The ancient tomb acts as a calendar that keeps perfect time.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

Some of the greatest minds in the history of Hungarian art and science converged in this café.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

This unassuming tree stump reportedly traces its roots to the famous pharaoh queen's reign.

A network of ancient Egyptian tombs built into the cliff face along the Nile.

One of its engravings is believed to be among the first representations of medical and surgical instruments.

The largest known Ancient Egyptian obelisk.

This ancient structure is widely thought to be the oldest intact pyramid in the world.

These Egyptian statues have survived for 3,400 years and were an acoustic wonder of the ancient world.

An alien landscape of chalk-rock in the Egyptian desert.

Ozymandias’ time-keeping temple.

A new sculpture calls attention to climate change in the centuries-old city it threatens.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

A sinister pyramid in the Frari contains the heart of the famous neoclassical sculptor.

A rather vulgar example of the transition from Latin to the Italian vernacular.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

A Nesting Doll of Churches.

The "Greatest Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

This 1920s Amsterdam neighborhood was built as a giant experiment in concrete construction.