The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.

Islanders once used this dramatic, otherworldly landscape to hide their cattle from Viking raiders.

Ancient cliffs resembling a kilt on Scotland's second largest island emit an entrancing sound.

The first rural cemetery west of the Mississippi is home to the elaborate tombs of St. Louis' local beer barons.

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

This titanic oil company sign is a reminder of the Americana boom of the 1970s and also its commoditization.

What was meant to be a temporary exhibit is now a permanent fixture at the St. Louis Zoo filled with beautiful birds.

This narrow coastline trail through the dense Kauai wilderness is among the most beautiful and dangerous in the world.

Take shelter from Hawai'i's tropical heat under the massive canopy of largest Banyan tree on the island.

This blowhole is supposedly caused by a trapped monster.

The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

A prehistoric landscape hidden in the cliffs of Maha'ulepu.

A once-glowing grotto at the bottom of Waikapalae Wet Cave.

This industrial area was the dumping ground for massive amounts of trash, some of which washes up as tiny bits of sea glass.

Earth's tallest volcano is sacred to Native Hawaiians, and home to a dozen world-class observatories.

This black shoreline is made up of exploded lava particles.

Race through the maze, get your name on the sign.

One of only two commuter aerial tramways in the United States.

A crumbling hospital from the 1850s on Roosevelt Island.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

A magical sinkhole on the Yucatán Peninsula is adorned with mini waterfalls and hanging vines.

Every equinox this Maya pyramid puts on a spooky ancient light show.