An emerald-green grotto just a short trip from Austin.

St Bernard de Clairvaux Episcopal Church, better known as one of the oldest European buildings in the Western Hemisphere.

A scattered trail of street art adds a pop of color to the city's stark structures.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

A colorful Peruvian city of the dead.

This historic, palatial theater is now one of the world’s most beautiful bookstores.

The land is home to swimming ponies and a legendary 18th-century treasure.

France's Lilliputian park displays over 100 of the country's monuments for visitor perusal.

This Berlin island is home to a flock of free-roaming peacocks, as well as a historic ivory folly.

Just outside of Nairobi lies a large estate surrounded by endangered Rothschild giraffes, who have been fed from the window by Mick Jagger and Walter Cronkite.

17th century mosque for Shah Abbas' harem.

An underground city of salt.

A series of waterfalls so massive they straddle the border of Argentina and Brazil.

Three and a half miles of cliffs, rocky beaches, Gilded Age mansions and 40 Steps to nowhere in particular.

This little-known collection holds everything from "Dracula" notes, to the manuscript of "Ulysses," to the forged works of Shakespeare.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

One of the last Jazz Age "Wonder Theaters" in New York City.

On the Oregon coast there is a natural hole that seems to be draining the sea.

The unbelievably opulent home built for an infamous newspaperman.

A castle built for love, and abandoned due to heartbreak.

The only land territory disputed between the U.S. and Canada.

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

"Dark Sky Park" is heaven on Earth for astronomers, one of the rare U.S. locations with no artificial light pollution.

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.