This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

Unrepaired walls from a 1920 anarchist bomb attack.

The last living thing to come out of the rubble after 9/11 is now a symbol of hope and resilience.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

A backdoor to Machu Picchu that only the most foolhardy infiltrator would attempt to breach.

A remote candy-striped mountain in the Peruvian Andes straight out of the pages of Dr. Seuss.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

These pretty kitties killed and ate as many as 135 railway workers.

The only Bahá'í house of worship in North America and one of only a handful worldwide.

G.V. Black, the Father of Modern Dentistry, keeps an eternal eye on Chicagoan’s teeth from his perch in Lincoln Park.

All of Chicago's wood-paved streets are long gone but two alleys remain.

A monument to the art of slicing people open.

A strange and haunting monument of unknown origin in the historic Graceland Cemetery.

A haunting statue called "Eternal Silence" has quite the reputation among visitors with active imaginations.

An enormous park-like oasis, full of famous Chicagoans’ graves.

A lush green oasis in the middle of Chicago.

Each of these gorgeous, intricately decorated rooms is painstakingly crafted to the scale of 1 inch: 1 foot.

Fragments of architectural wonders from around the globe are embedded in the newspaper building's walls.

The 606 is a decade in the making.

A Bibliophile's Dream.

A gothic church spire sits atop this skyscraper, the tallest church in the world.

This whimsical Oz-themed park had a wonderful impact on the surrounding neighborhood.

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

This $3 million model train takes you through Chicago, Seattle, and the thousands of miles in between.