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.

This underground transport hub doubles as an art gallery.

A reconstructed medieval gateway that was the magnificent entrance to the capital city dating back to 1037.

The haunting complex honors the millions of Ukrainians who died in the forced famine under Soviet rule.

This abandoned Soviet circus is slowly being restored to its Communist-era glory.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

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

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

A statue of the legendary Celtic warrior queen who fought the Roman invaders stands in one of the cities she once destroyed.

More than a million titles fill the labyrinthine shelves of this prestigious private library.

Giant, friendly pelicans in Central London, the most unlikely of places.

The vaulted ceiling is home to a scurry of “squirrelgoyles.”

The world’s first museum dedicated to exploring human rights unleashed a wave of controversy.

A small museum in Newfoundland is home to a 227-foot tapestry that preserves the remote region's colorful history.

The only town in the world with two exclamation points in its name.

This monster fiberglass crustacean stands watch over the self-proclaimed "lobster capital of the world."

A mysterious spot where the laws of gravity seem not to apply.

Twice a day, the water of the Petitcodiac River flows upstream in a surfable wave.

Alongside a scenic road are the remains of crumbling World War II gun emplacement.

A beautiful waterfall and beach where precious stones are plentiful.

Iconic rock formations that allow for exploration during high or low tide.

A complicated, forgotten beacon of hope for thousands of immigrants, "Canada's Emerald Isle" lies in ruin.