The "World's Largest Underground Business Complex," a 55,000,000-square-foot city underneath Missouri.

This majestic tree has survived 400 years of storms, droughts, and floods, and is a beloved natural landmark in Missouri.

Two Ming Dynasty lion statues guard the entrance to the journalism school.

The seventh largest spring in the world.

A home designed to be on the cutting edge of comfortable, low-cost living.

Breathtaking and huge 430 year old maps of Italy.

This tea house was a hand-built gift from Boulder's sister city in Tajikstan.

Two stone columns flank the grand Venice square, but there were supposed to be three.

A copy of the famous statue can be found in this Florence piazza, along with one of the most breathtaking views of the city below.

The world's largest collection of the world's largest objects is in one small Illinois town.

This inanimate goat created by the "welding nun" has been helping to clean up the city of Spokane for more than 40 years.

A museum dedicated to the history and exploration of both popular music and science fiction.

Race through the maze, get your name on the sign.

An authentic replica of an Asian temple and garden hidden amongst the natural beauty of Hawai'i.

A series of waterfalls and pools that flow through the 'Ohe'o Gulch and into the ocean.

Take shelter from Hawai'i's tropical heat under the massive canopy of largest Banyan tree on the island.

Ten acres of the Kula Forest Reserve make up this wondrous state park.

This black shoreline is made up of exploded lava particles.

This museum of Hawaiian and Polynesian culture is the legacy of the last descendant of the Kamehameha Dynasty.

An unexpected but incredible collection of wildlife dioramas spanning rainforests, swamps, forests, and plains.

A diverse, expansive nature preserve in northeastern Kansas.

It's big, it's a ball, and it's made of twine—the world's largest of its kind.

A vineyard devoted entirely to an unexplored flavor frontier.

The iconic remains of the original Academic Hall that burned down in 1892.