The world's largest wooden structure.

Spanish architects used seized Muslim gravestones to rebuild parts of the fortress.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

This Parisian gem is one of the most incredible ethnographic museums in the world.

A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the century.

This life-size replica of the Statue of Liberty's flame is also a tribute to Princess Diana by default.

This bridge was constructed from the rubble of the infamous Bastille.

The celebrated eyesore created by starry-eyed sweethearts.

The spiral staircase hidden inside this giant Parisian column was likely built for Catherine de Medici's astrologer.

The oldest continuously operating mint in the world that has been making coins since the 9th-century.

Walk upon the mementos of the dead in this Parisian courtyard paved with medieval tombstones.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

The narrowest street in Paris.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

The precise origins of this pink sandstone temple are unknown.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

A Gothic-inspired fish market is Gothenburg's best place to find loaves and fishes.

This simple roadside art installation ended up sparking a folk art movement and a controversy of international proportions.

The ruins of a monastery where Saint Bridget of Sweden had her revelations recorded.

This encrypted monolith protected a secret of Norse mythology by hiding in a church wall for over a millennium.

Enigmatic bug-like sculptures mystify drivers along a Swedish highway.

The standard measure of Lagom, a measure of what is enough.

The marker that allows students all over the world to be late for class.