A long-forgotten Victorian swimming hole is still a fun spot for a dip.

Take a dip beneath the stalactites in this amazing cenote.

This geothermal hot spring hides beneath a slowly growing mineral dome.

A perfectly circular lake is formed by the crater of an ancient underwater volcano.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

This oak sculpture at the edge of a small woodland is nine feet tall and shrouded in mystery.

Twisted trees shaped by coastal winds make this woodland look like something from a spooky story.

Some call this eerie forest of crooked trees the "Bermuda Triangle of Romania."

This location of a Mexican chain restaurant has a unique location: an old jail.

Home to New Mexico's longest bar, this watering hole also has a mining museum and a haunted history.

During the holidays, a vintage subway train whisks New Yorkers back in time.

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

A haven for book enthusiasts across the street from Retiro Park.

Medieval ruins nestled within a breathtaking swath of Spanish nature.

Known as the Casa de las Siete Chimeneas, this haunted 16th-century manor has a dark, mysterious past.

Remains of the lost church hide beneath this Spanish Parliament building.

This piece of early engineering is rather unknown despite its location in the heart of Madrid.

Along the pavement of this neighborhood in Madrid are quotes from famous authors.

A statue commemorating a beloved stray dog who was adopted by the entire neighborhood where he lived.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

One of Madrid's oldest trees, with a long and colorful history, resides in El Retiro Park.

The remains of the second-oldest zoo in Europe can be seen within these library gardens.

The remains of this misplaced church were moved here stone by stone.

Once a resting spot for King Fernando VII.