The only remaining U-boat that is still floating never actually saw any action in World War II.

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

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

This unauthorized stone mermaid was secretly carved out of public stone before being permanently preserved.

One of the largest aviation events in the world brings half a million aircraft enthusiasts to Wisconsin each year.

This beacon for pre-radar pilots once guided Charles Lindbergh to a safe touchdown in Tulsa.

One of the last remaining Carpenter Gothic churches is situated on a wildflower conservatory overlooking the bay.

One of the best examples of Art Deco architecture in the United States.

The fifth tallest statue in the United States is a shirtless monument to the oil worker.

This abandoned, windowless concrete block is one of the strangest buildings in Tulsa.

This house renovated by Frank Lloyd Wright was the centerpiece of a lavish 20th-century estate.

The collection is housed in an exquisite mansion that makes you feel like you've been transported to an Italian villa.

Songwriter Leon Russell transformed this church into a recording studio used by many legendary musicians.

A small museum filled with over 1,000 clocks, and one particular clock calibrated to run until the year 9999.

The only surviving prototype of Buckminster Fuller's revolutionary car.

A hands-on traveling collection of the innovative devices of yesteryear.

The only surviving prototype for Buckminster Fuller's house of the future.

The 80-foot tire that looms over Michigan's I-94 was once a Ferris wheel in the New York World Fair.

Colorful lights and mirror-like brine pools create trippy illusions within the historic mine.

The pieces in this sculpture garden are made from demolished buildings that were once landmarks of Motor City.

Diego Rivera's massive tiled fountain and failed infrastructure project.

66,000 pieces of art, donated by one of the world's richest men.

Naturally protected city carved from a rock face.

A quirky house created entirely out of glass bottles combines a collector's spirit with an artist's flair.