This WWII-era military installation once held an entire city within its walls - now, its walls are falling down.

This small city where almost everyone lives in the same building can only be reached via North America's longest tunnel.

Running under an entire mountain, the longest highway tunnel in North America is kept fresh using portal fans and jet fans.

The only house built with a turret, crenellations, and a moat in Palmer, Alaska.

This abandoned mine offers a glimpse at what life was like for those who came to Alaska seeking Gold Rush riches.

This Alaskan town appoints the general store's resident feline as honorary mayor.

Four-story concrete hotel never opened to customers.

A copy of the famous bus used during the filming of 'Into the Wild' is on display at an Alaska brewery.

A giant poultry statue immortalizes one of Alaska's more humorous town names.

The northernmost international land border crossing in the United States.

The resilient spirit of this remote mining town burns bright in its eclectic memorabilia.

A historic signpost to world cities on the top of a barren mining hill in the Yukon.

This decommissioned DC-3 now forever points into the oncoming wind.

When the big city meets the edge of the frontier, log skyscrapers are born.

The arch marks the beginning of the road for northbound travelers.

At a lodge and RV park is a collection of headwear that comes in at more than 11,300 and counting.

Roadside collection of 65,000 signs.

Whimsical cartoon cars suspended on posts soar over an automotive shop.

This prehistoric sinkhole lured exclusively male mammoths to their death, much to the delight of science.

The oldest extant wooden jail in South Dakota and possibly the United States. 

Home to the world's largest quilt collection dating from the 1600s through today.

See the world's biggest spool of thread, along with the largest collection of sewing machines.

The longest of the four remaining covered bridges in Missouri.

This 40-foot fowl marks the so-called "wild goose capital of the world."