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.

This legendary city has been a tourist attraction for centuries.

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

The hallucinogenic center of the ancient world.

Monasteries on rock pillars, once accessible only by frayed ropes.

This memorial to the victims of the Romanian Revolution of 1989 is often compared to a potato on a skewer.

Romania's triumphal arch looks out over Bucharest.

A fire once nearly devoured this gorgeous 14th-century Gothic cathedral.

The European towns of Brașov and Râșnov each have proud signs reminiscent of the Hollywood sign.

This snug medieval lane is one of the narrowest streets in the world.

Something's watching you.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

This once-derelict building is now one of the most beautiful bookstores in the world.

Once one of the largest rooms full of books in the world, this bookstore basement is still a treat for bibliophiles.

A 26-foot shark sculpture—a statement about bombs—set off a municipal battle royale.

One of Europe's oldest libraries.

Standing atop 2nd-century Roman ruins, this church is one of the oldest and most iconic in Old Cairo.

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.