A 'living museum' in Leiden, the oldest of its kind in the Netherlands.

A market built atop boats is one of the few floating holiday markets in Europe.

This centuries-old gothic monster has been converted into a sprawling, glossy bookstore.

These slanted cubic abodes are a creative if odd solution to a zoning pickle.

Colorful and chaotic stacked hotel in North Holland.

Inspired by "The Starry Night" this Dutch bike path turns into a glowing work of art each night.

Peek through a transparent pyramid and drink in the mountain made of books.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

The last remnants of a massive medieval wall that once encompassed the city of Berlin.

One of the most easily accessible examples of the rare 1960s UFO houses.

Hamburgers are intensely proud of their tunnel beneath the river.

These brass bunnies honor the rabbits that dominated the no-man's-land around the Berlin Wall.

This historic stone bridge has an entire neighborhood clinging to its sides.

Started as a kitchen garden, now the second largest botanical garden in the world.

These magnificent city walls rise from the barren sun-baked Spanish plains like something straight out of a fairytale.

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

An enchanting monastery in the Spanish countryside appears lifted from a fantasy tale.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

This former Baroque palace on the historic Calle Montcada is a rare architectural gem and was once the meeting place of an aristocratic scholarly society.

A lush indoor jungle fills this bustling Madrid transportation hub.

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

Bacteria and algae give the salty water its bubblegum hue.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

This steep cable railway has been hoisting passengers in the heart of Québec City for over a century.