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

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.

The first declared National Monument in the United States.

Two thousand artifacts from around the world collected by one woman who loved to travel.

Home to items never before seen by the public.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

The oldest cemetery in New Orleans, resting peacefully for over 200 years now.

One of the oldest used bookstores in the U.S. has been selling antiquarian treasures since 1825.

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

Get lost in this haunting fairytale art walk through a man-made eucalyptus grove.

Enormous lake at the bottom of a unique cave system.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

A 200-year-old bar in the historic French Quarter refuses to give up its place in history, nor its role in securing ours.

Resting place of Hollywood's immortals is also site of summer film screenings.

Elevated freight railway turned wildly successful urban park.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

A collection of oddities including Dr. Kevorkian's suicide device, the Thanatron.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

Dramatic river bend surrounds a natural red-rocked pedestal.

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

An enormous, inside-out glass globe built in 1935.

An artsy hidden staircase leads to breathtaking views of San Francisco.