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

The deadliest diving spot in the world is also a stunning geological marvel.

The massive cave church of Cairo's Zabbaleen community is one of the largest Christian churches in the Middle East.

This living labyrinth made entirely of thorns is filled with art.

The mouldering manses of wealthy colonials still pock the streets of a Curaçao neighborhood.

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

A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.

This mesmerizing kinetic sculpture blossoms endlessly in the breeze.

Two thirds of this Montreal neon icon has survived to flash another day.

The biggest museum dedicated to insects in North America, one of the largest in the world.

Montreal's giant farmer's market is a foodie's best friend, especially in the winter months.

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

The world's largest collection of Don Quixote-inspired art.

A Mexican Romeo-and-Juliet-esque legend has given this super-narrow alleyway a reputation for romance.

Mexico's astounding mummy museum with "the world's smallest mummy."

After Christopher Columbus died, his son built a fancy house to rule from.

Cavernous opening completely encased in Karst limestone.

Hundreds of iconic jazz records were made in this church-like space.

The remnants of an abandoned, 19th-century gold mill along Aruba's rugged northeastern coast.

A safe place for the wild donkeys of a hot vacation destination.

On any given day this sprawling market houses literally tons of government-regulated gold, gems, and precious metals.

A preposterously luxurious hotel with gold-plated iPads, Rolls Royce chauffeurs, and a staff that trains by watching "Downton Abbey."

A strange aquarium with stuffed fish, and almost no water for them to swim in.

This ancient structure is widely thought to be the oldest intact pyramid in the world.