The slate extracted from these Pennsylvania quarries was once hailed as the finest in the world.

Although built to generate electricity for Marylanders, this dam has become an all-you-can-eat buffet for American bald eagles.

Once decrepit and slated for demolition, now one of the longest pedestrian bridges in the world.

Ancient catacombs form the foundation for this Rococo orgy of a church.

The stunning interior of this Gothic church is covered in ornate gold details.

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

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

This beautiful, historic church looks like something out of a simpler past.

Walk in the footsteps of the gods and straddle two tectonic plates.

A relatively obscure antihero from the Marvel Comics universe adorns a wall inside Iceland's main airport.

A geothermal paradise with bubbling mud pools and bright blue hot springs.

One of the oldest family businesses in Reykjavík serves lamb-based hot dogs.

This aromatherapy shop and mini-museum cofounded by the Sigur Rós frontman documents Icelandic history through scents.

This tiny museum's sizable collection is jammed into a former underground public toilet.

This fantastical waterfall is hidden in a cave located in a cracked cliff.

Three columns of volcanic rock shoot out of the ocean.

A black sand beach where glacial fragments wash ashore and look like sparkling diamonds.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

This skeleton-filled altar piece served as a backdrop to one of the most iconic scenes in "The Sound of Music."

Terrifically morbid cemetary and site of famous Paracelsus' grave.

Visiting this café is like visiting the Austrian grandma you wish you had.

The townhouse where the "Blood Countess" Elizabeth Báthory started her murderous career.

The final resting place for the remains of 143 Habsburg royalty.