This giant disembodied horse head seems to balance impossibly on its nose.

Underneath the historic center of Mexico City, the remains of a temple dedicated to the Aztec god of the wind.

This cemetery served as the only official burial grounds in Cambridge for nearly 200 years.

This quarter-mile tunnel under the Bluff in Pittsburgh bends at a 45-degree angle.

Obscure Freemasons still live in D.C.’s largest private residence.

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

This unacceptably tall building was the real reason for Washington, D.C.'s skyscraper ban.

This turn of the century masterpiece has a mysterious goaty interloper.

The remains of a ruined mansion memorialize the 1906 earthquake.

A nondescript building that's been functioning as a speakeasy for nearly a century and a half.

A museum befitting the city responsible for supplying the majority of the world's LSD.

A huge musical instrument played by the ocean.

This theme park presents 5,000 years of Shanghai history and includes a "sunken" exhibition hall.

A memorial to those who died at the hands of the Kuomintang while fighting for communism in China.

A striking depiction of Teotihuacan's mysterious "Spider Woman."

This pre-Hispanic apartment complex also includes ancestral paintings that point to its military past.

Dating back to the second century, vestiges of prehispanic mural paintings are found in this underground palace.

This strange sculpture of a menacing skull surrounded by sun rays was discovered at the foot of the Pyramid of the Sun.

This ancient jade mask depicting the Zapotec bat god was found in the ruins of the pyramids of Monte Alban.

The striking jade death mask of an ancient Maya king is displayed in a replica tomb in Mexico City.

This colossal ancient sculpture of the monstrous Aztec rain god has a literally stormy history.

These spectacular, symbolic serpents lie within the shadow of the Great Temple.

This colossal ancient jaguar sculpture was used as a vessel for the hearts torn from sacrificial victims.

Come face to face with the ferocious visage of the serpent-headed mother goddess of the Aztecs.