One of the largest underground systems runs under Canada's largest urban center.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

The celebrated eyesore created by starry-eyed sweethearts.

This bridge was constructed from the rubble of the infamous Bastille.

This demon atop the Notre-Dame de Paris looks utterly bored.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

Site of a classic 19th-century physics experiment to prove the earth is rotating.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

A particularly disconcerting tribute to Irish martyrs.

The somber sculptures commemorating Irish Famine on the river Liffey in Dublin.

The comedy and tragedy of Oscar Wilde is preserved in a Dublin park, captured in a sculpture of colorful stone.

Experience what life was like in Ireland during the Viking and medieval ages.

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

Inside this 3,500-year-old tomb are remarkable ancient Egyptian paintings of African wildlife.

The ancient village known as Set Maat, or the 'Place of Truth,' located on this site served as a hub for intellectual and artistic endeavors.

The medieval center of the Islamic world was also once the seat of Saladin's sultanate.

The once great capital of Egypt now crumbles forward as evocative ruins.

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

The largest known Ancient Egyptian obelisk.

In Egypt's expanding metro area, many of the neighbors are dead.

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.

Known as the Sistine Chapel of Egypt, this tomb houses some of the most well-preserved paintings in Egypt.