An unusual slot canyon in the Aztec/Navajo Sandstone has a cross-section like an inverted old-fashioned keyhole.

This 12-seat movie theater is the smallest in the world.

The ruins of a resort and casino sit on the banks of this blue hole spring that pumps 70,000 gallons of warm, clear water every minute.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

Monty Python fans will recognize this abandoned mine as the Cave of the Killer Rabbit of Caerbannog.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

This centuries-old Italian chapel hangs midway down a sheer cliffside.

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

An unassuming secret door once led to a legendary watering hole.

The translucent turquoise hue of these natural swimming pools comes from a high concentration of minerals.

This wildlife refuge is home to more than 200 species of birds, as well as monkeys, lizards, and other wildlife.

Costa Rican accommodation resembles a crash site, but with a nice balcony.

In Costa Rica's cloud forest, the roots of a woody ficus create a botanical bridge.

One Costa Rican island is so beset by illegal shark poachers that the local rangers have built an entire bridge with their confiscated gear .

Once the foundation for a mansion, these ruins now offer amazing panoramic coastal views.

Balanced rock sculptures pay tribute to a murdered conservationist and his pioneer wife.

There is a small island in the Gulf of Nicoya where the only human inhabitants are dead.

Inside the simple black-and-white exterior of Église Sainte-Cécile hides a pastel wonderland.

The "birthplace of insulin," where Sir Frederick Banting realized the hormone could save the lives of Type 1 diabetics.

This towering bee statue is a tribute to Ontario's first meadery and a century-old honey producer.

The world’s oldest baseball field had to fight to earn its record.

The dairy farm in upstate New York where nearly half a million people gathered for three days of peace and music in 1969.

This otherwise innocuous bodega was once the headquarters of the most feared assassin's guild in American history.

An abandoned castle owned and ignored by Masons carries a cursed history.