Board a mine car and descend the #190 slope 300 feet underground into the Clark Vein of coal.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

The ruins of an ancient stadium that hosted gripping chariot and horse races.

The naval commander’s proudest moment in battle is memorialized in this unique tomb at Arlington Cemetery.

The romance of early commercial flight still fills this Art Deco destination.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

This unique historical monument features large concrete spheres designed to resemble fallen stars.

Soldiers were buried next to Lee's house in the center of Arlington Cemetery to dissuade the general from reclaiming his property after the war.

The rogue roots are gradually consuming some of the historic marble grave markers.

An eight-sided home built during a brief octagon craze in the 1850s.

A giant "X" symbolizes the blood spilled from the brutal Juárez drug wars.

Tijuana's legendary jai alai or "basque ball" palace is now a massive music venue.

The Old Courthouse takes visitors on a captivating trip through St. Louis' timeline.

This Yellowstone geyser may not shoot as high as the nearby Old Faithful, but it erupts for considerably longer.

The only natural lake in the world that drains into both the Atlantic and Pacific Oceans.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

An architect's childhood fantasy treehouse made real.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

A beautiful geyser under environmental threat.

Modeled after a famous church in Vienna, Austria—but in Helena, Montana.

A 400-square foot model of historic Quebec is the playing field for a state of the art light and sound show.

This former prison now houses a lovely library devoted to Quebec's oft-maligned English-speaking history.

A contemporary fresco movement illustrates the region's rich history.

This steep cable railway has been hoisting passengers in the heart of Québec City for over a century.