In this case, 'zero' marks the spot where the iconic Old Spanish Trail ends.

This glass-stain Mary attracted thousands of pilgrims until her head was shattered by a vandal with a slingshot.

An 18th-century Spanish watchtower made entirely of seashell and concrete.

Public works and national defense project meant to carve a canal all the way across the state of Florida.

This abandoned NASA launch site is now a memorial to a trio of astronauts who were killed there.

A building so large that it has its own weather.

The culprit who accidentally lit this 3,500-year-old tree on fire stated "I can't believe I burned down a tree older than Jesus."

Center filled with hands-on displays served as a tribute to several astronauts with connections to the state.

Largest tulip festival in America, includes fireworks, a parade, and a carnival.

Strange physical sensations and optical contradictions keep visitors coming back for more.

Island where motor vehicles are banned -- home to the only carless highway in the United States.

This shallow cave got its name from copious amount of human bones found inside.

The fifth-longest suspension bridge the world, connecting one Michigan peninsula to another.

One lonely, modern pyramid has gone from corporate think tank to deserted boondoggle.

World's largest Christmas store.

This national park on the shore of Lake Michigan features remarkable dunes that lie at the heart of a Chippewa legend.

Part taxidermy workshop, part natural history museum this Michigan destination shows off its dead animals and helps you mount your own.

This log cabin gallery is one man's gnarly, hand-carved tribute to his favorite trees.

A former major munitions plant that has been converted into a sprawling art space.

The "lovely red Vega" of the legendary record-settling pilot.

Home to items never before seen by the public.

This pre-Revolutionary War grist mill ground corn and flour for soldiers in seven American wars.

Outsider art meets paleontology at this roadside reptile repository.

A modern tower, symbolizing the legend of a golden egg on top of the tree of life.