Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

An ancient Egyptian temple in the middle of Madrid, Spain.

The world's oldest bookshop still in operation.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

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

The ruins of an ancient Roman tomb hidden in the basement of a trendy clothing store.

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

This gem is often wrongly overshadowed by the larger, newer Metropolis church in Athens.

This ancient hydrological marvel is now the base of a modern outdoor cinema.

An ancient octagonal weather station named for the eight Greek gods of wind.

Large collection from the 3rd millennium BCE.

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

150 or so scrounged-up lamps, chandeliers, and lanterns light up this alley in central Athens.

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

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