A monument marks the beginning of the longest north-south road in the United States.

The remains of a large iron mill that once stood in the remote woods of northern Maine.

Steam engines and conveyor belts are remnants of a genius system left in the middle of the Maine woods.

The highest point in Washington state is a volcano covered in glaciers.

The king of U.S. high points towers over every other peak on the continent.

A son's promise to his dying father in the form of a covered bridge filled with thousands of seashells.

One of the largest wooden ships ever built is honored by a steel sculpture evoking her once-superlative scale.

The most photographed house in Maine looks good enough to eat.

An unusually designed bridge from the 1920s was built to withstand the tides and winds of Maine.

The world's oldest and largest museum of mass transit vehicles.

A mural of a boy making a phone call connects a southern Maine community to a town in Iraq.

The world's only international cryptozoology museum is host to an unrivaled collection of mysterious objects.

Its unique collection details the history of the state's svelte railroads.

The only remaining historic maritime signal station in the United States.

This lower Manhattan bar is set up in an old bank vault that rests beneath a skyscraper that hides even more historic splendor.

Just your average Marie Antoinette–themed speakeasy in an abandoned 19th-century subway tunnel.

A secret door leads to this cozy dive that sells only “milk.”

Cool down and fill up after visiting Teotihuacán at this bar and restaurant in a deep, underground cave.

A subterranean house of worship carved right out of the bedrock.

A Cold War atomic camp buried under the ice is now emerging because of global warming.

The third-largest island in Canada is one of the remotest places on Earth.

The world's northernmost flowers cling tenuously to life on desolate Kaffeklubben Island.

These hellish-looking cliffs in the Canadian Arctic have been burning for centuries.

Traces of the thriving lake trade that once linked the Soviet Union with Mongolia.