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

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

A clone-tree in Washington Square Park sprung from seeds that went to the Moon and back.

A layered tribute to the work of mosaicist Isaiah Zagar.

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.

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.

The twin towers in this Chicago fountain use 50 foot tall video screens to spit on people.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

A massive volcanic plug is now a protected area that hosts a number of bird species.

The unbelievably opulent home built for an infamous newspaperman.

Only hotel where you can legally launder money.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A sculpture of the famous photograph stands on San Diego's "Greatest Generation Walk."

A modern day curiosity cabinet.

After starting as a whimsical tourist attraction that eventually found its way to ruin, these renovated canals offer a lush and exotic locale on the Pacific Coast.

The final resting place of a space program monolith.

The legendary building that needed ghostly approval before being built.

High on a hill overlooking Los Angeles lives a world famous, high power conical Tesla Coil.

World's largest Christmas store.