On a clear day, you can see all the way to the Virgin Islands from the top of this observation tower built in the 1960s.

This bleach-white graveyard overlooking the ocean is accessed through a tunnel.

Legend tells how a Spanish soldier disappeared from this isolated sentry box without a trace.

This colorful gate stands as an entrance to the walled city of Old San Juan.

This chapel on a cliff is renowned for its healing powers and was founded on the site of a supposed divine intervention.

A park where people have been going to feed friendly pigeons since the 18th century

This ultra-modern California span is actually a titanic solar clock in disguise built by famed architect Santiago Calatrava.

Sunset-colored dunes of volcanic ash make taking a poor photo impossible.

Canyon walls shrouded in ferns.

The flow from this waterfall sometimes comes out of springs below its rim.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

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

A carnivorous plant paradise in a serpentine bog.

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

A restored Pittsburgh house of God has been converted to a marvelous house of suds.

The site of the little-known Pennsylvania battle that sparked the Seven Years' War.

This kitschy tavern is also home to rare early editions of "Treasure Island."

An early-19th-century hotel with a past that is steeped in the Civil War.

This quirky curiosity shop takes its cues from the world's bazaars.

"X" marks the spot of an echo chamber in the middle of a plaza.

A once-groundbreaking power plant turned into a hotel and mini-museum of archeological and geological wonders.

One of Savannah's oldest and most haunted cemeteries, featuring graves desecrated by Sherman's Union Army.

A monument to one of the few Olympic flames ever to be lit outside of the host city.

A statue honoring 44 continuous years of greeting passing ships.