The colonial city's social history is reflected in its fanciful door knockers.

Home to 23 voluptuous and instantly lovable sculptures by one of Latin America's most celebrated artists.

An unusual and beautiful form of mass transit serves the city's steepest neighborhoods.

Two identical statues by Fernando Botero, one blown to pieces in a terrorist bombing, the other donated as a gift for peace.

The sounds of the world's largest fully functioning pipe organ dazzle shoppers at a Philadelphia Macy's.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

The Andean town where every single building is decorated with a brightly colored frieze.

A 10 million-ton rock once worshiped by the Tahamies Indians, accessed by an astounding staircase.

Golden and naked, the figure that was once the highest point in New York is all that remains of the second Madison Square Garden.

Ant sculptures march up the side of what used to be an iconic spot in punk rock lore.

This elaborate towering structure was once famed for its revolutionary height.

Yo, Adrian!

The oldest surviving botanic garden in the United States.

The first American department store, and home to the largest operating musical instrument in the world.

Dr Barnes' $25 billion private collection of art and arboretum.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

World's first "penitentiary," meant to be humane, drove men insane.

A layered tribute to the work of mosaicist Isaiah Zagar.

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

Real bones which are said to have belonged to a Polish dragon.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

Boats must transform into railroad cars to navigate this Polish canal.