For part of the year, this innovative greenhouse is painted white to keep the plants from getting scorched.

This Victorian-era public house has set the standard for pub-style elegance for over a hundred years.

Northern Ireland's Brobdingnagian stepping stones.

The oldest pub in Ireland may also be the oldest surviving bar in the entire world.

An 80-year-old plane tree is devouring an iron bench at Ireland's oldest law school.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

Drink wine handed out through a window as part of an age-old tradition.

Someone loved this song enough to carve all of its lyrics onto a tree trunk in a Berlin park.

A spectacular rainbow of stained glass makes the "Pink Mosque" one of the most beautiful in Iran.

A dreamy mausoleum honors Persia's most famous poet.

The palace of the King of Kings, burned by Alexander the Great.

Mirrors and glass shards cover every inch of this arrestingly beautiful mosque.

A medieval weapon rumored to have been used by the brilliant poet himself.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

Hear the quietest sound from across the dome.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

The "Seinfeld" diner.

This unmarked and unloved Manhattan subway grate created one of the most iconic images in American cinema.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

Climb this overlooked gem's spiral staircase and you'll be rewarded with spectacular views of Glasgow.

The Columbia Road Flower Market is now open every Sunday, rain or shine.