Largest Roman Catholic church in North America.

During the Industrial Revolution this “Temple of Invention” was full of intricate miniature machines and gadgets.

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

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

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

This museum celebrating the almighty dollar lets visitors literally stand in the shadow of a million bucks.

A 1,100-ton train fell through the floor in 1953. Workers got it patched up in just 72 hours.

An unassuming, powerful monument north of the U.S. Capitol bears witness to the resilience of Japanese Americans during a time of grave injustice.

A tiny monument to the unsuccessful attempt by Thomas Jefferson to place the prime meridian in Washington.

A line of blue paint marks the route of the inaugural parade.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

Dedicated to the art and science of glass in equal measure, this space is as much laboratory as museum.

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

The original vault that held the president's remains still stands, empty, not far from where he was finally buried.

When you visit his grave, be sure to rub the Great Emancipator's nose for good luck.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

The massive, incredibly rare instrument is over 11 feet tall with a range so deep it goes lower than humans can hear.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

Dramatic river bend surrounds a natural red-rocked pedestal.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

Every equinox this Maya pyramid puts on a spooky ancient light show.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.