The remains of an Aztec school and various intriguing artifacts lie below a modern cultural center.

A scientific repository of goiters, boils and other ailments throughout Mexican history.

This foreboding building was the headquarters of the terrifying Spanish Inquisition in Mexico.

Diego Rivera hid various people and symbols in his first large-scale mural project.

This museum houses two of Mexico's most impressive Aztec monoliths.

These haunting ruins of a 700-year-old Prehispanic city have witnessed centuries of wars and massacres.

66,000 pieces of art, donated by one of the world's richest men.

This immense scene of a cosmic battle between a jaguar and serpent illustrates the Aztec concept of the duality of life.

The last of Amsterdam's original sea level markers remaining in place.

This large copper bolt represents the benchmark for measuring sea levels in most of Europe.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

This unusual elevator doesn’t stop or slow down.

A Portuguese Jewish cemetery filled with stunning grave monuments that date back to 1614.

A rare tour of an aristocrat's private home reveals valuable 17th-century paintings from artists like Rembrandt.

A collection of biblical memorabilia.

The world's oldest Jewish library was founded by Sephardic Jews in 17th century Amsterdam.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

This unattributed sculpture in Amsterdam is hiding in plain sight.

This impressive collection of rare books on ancient mysticism inspired author Dan Brown.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

A floating cat sanctuary on an Amsterdam canal.

A unique collection of gilded age mechanical pianos.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.