This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

Mountain where Jesus was first tempted by the Devil.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

A New Zealand communications tower stands as the tallest structure in the Southern Hemisphere.

Major tourist destination known for its bubbling mud-pools and hot thermal springs.

A perfect turquoise lake colored with glacier dust.

Dolphins, ancient clams and hundreds of waterfalls make this one of the world's top tourist destinations.

Tubing through a cave lit with glowworms is a magical underground experience.

The real life Hobbiton, this sheep farm has been forever transformed since being built for The Hobbit film series.

A walk through the historic city center, under the streets of Seattle.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

Cathedral carved out of salt, located a mile below the earth's surface.

A 10 million-ton rock once worshiped by the Tahamies Indians, accessed by an astounding staircase.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

One of Catholicism's four major basilicas has a series of papal portraits that are said to predict the end of the world.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

2300-year-old Roman road connecting the empire.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

Rome's semi-secret peephole vista is also a former Crusader stronghold.