The building that inspired Shirley Jackson's "The Haunting of Hill House."

These unusual rooms on wheels are holdovers from the 1960s.

Herbert Hoover's "Brown House" rural presidential retreat was a PR disaster amid the start of the Great Depression.

An eerie, decaying ghost town destined to fade into the forest.

The only monument to name all of the passengers and crew who died on the RMS Titanic.

For part of the year, this innovative greenhouse is painted white to keep the plants from getting scorched.

Once the grandest synagogue in medieval Spain, it now stands as a memorial of the 15th-century Jewish exile.

The fragmented remains of a massive public bath connected to the city's water supply.

The Roman city was the birthplace of various emperors and is home to one of the empire's most impressive architectural feats.

A copy of the famous statue can be found in this Florence piazza, along with one of the most breathtaking views of the city below.

This castle has links to Portugal’s founding and struggles for independence.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

These ancient artifacts are a testament to the enduring significance of the bull in Spanish culture.

This enigmatic artifact is a rare depiction of an ancient Iberian noblewoman.

An iconic and controversial ancient Iberian funerary urn with a hauntingly penetrating gaze.

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

An ancient Egyptian temple in the middle of Madrid, Spain.

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

This macabre masterpiece of a mural is one of Francisco Goya's "Black Paintings."

The discovery of these rare, ancient artifacts led to the creation of a new museum.

This former charity hospital for elderly clergy houses some of Seville’s most treasured paintings.

The world's largest wooden structure.

This Gothic church houses ornate royal tombs and a magnificent gilded altarpiece.

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.