This natural marble cave is one of only five national monuments in Oregon.

Only known mainland rookery of the threatened Stellar sea lion.

On the Oregon coast there is a natural hole that seems to be draining the sea.

The largest wooden building in the world now houses a fascinating collection of aircraft.

Multiple waterfalls and several historic CCC buildings anchor this state park in Oregon's Willamette Valley.

Spectacular volcanic cliffs along the Crooked River invite hiking, rock climbing, and photography.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

Shakespeare has been brought to life in this open air theater for the better part of a century.

One small town in the Pacific Northwest transformed itself into a Bavarian-themed tourist destination.

Perhaps the world's only gas station inspired by a political scandal.

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

Red sandstone structures dominate this landscape, which has been inhabited for some 5,000 years.

This balancing rock is one of Utah's most unusual geological formations.

The location where the iconic movie character declared it was time to go home.

Few things look more out of place than the electric blue ponds in the reddish-brown desert of Utah.

This memorial includes fragments from one of the greatest tragedies in United States history.

Thousands of pieces of art have been carved into the rock at the site of an ancient volcanic eruption.

One of the most well-preserved temples of ancient Egypt.

The medieval center of the Islamic world was also once the seat of Saladin's sultanate.

This ancient structure is widely thought to be the oldest intact pyramid in the world.

Known as the Sistine Chapel of Egypt, this tomb houses some of the most well-preserved paintings in Egypt.

These Egyptian statues have survived for 3,400 years and were an acoustic wonder of the ancient world.

As if T-rex wasn't big enough, this Canadian monument is four times larger than the real thing.

A standalone wonder amid the prairie badlands of southeastern Alberta.