This still-celebrated home was a radical architectural experiment in 3D De Stijl.

Underground attraction offering tours of the foundational ruins of a church nave that collapsed in 1674.

This Netherlands museum holds a gloriously mechanical collection of ornate musical automata.

Atop this former dutch railway office sits an interstellar work of art.

A uniquely preserved neo-Gothic church that is now home to a collection of art and woodcarvings.

The largest airborne operation in history was launched to capture this bridge.

Organisms normally seen under a microscope decorate this church.

A late-medieval Dutch castle with trick fountains in its whimsical water gardens.

A set of beech hedges planted in the 19th century forms a tunnel that takes on a different appearance in every season.

An idyllic hotel that gave its name to a supposed shadow government.

This giant radio telescope would be a rusting ruin if it hadn't become such a beloved relic.

This beautifully designed star-shaped fort was the premier defense system of the late 1500s.

Secret Swing.

This concrete church spent a period of its history as a World War II bunker.

A poignant mural honors the heroic teenage non-conformists who took on the Nazis and paid the ultimate price.

How did a lighthouse wind up in the middle of this landlocked German city?

The largest mosque in Germany.

This ducal residence was once home to a future Russian empress and a French king in exile.

This German art chapel is perfect for those who like their worship hard, modern, and utterly alien.

A ruined castle stands atop a hill surrounded by dragon lore.

This former Nazi castle was built as a school to train what would have been the future of the Third Reich.

A top-secret bunker now turned museum, is an eerie look at what life would have looked like in the event of nuclear war.

The door to the museum holds a unique artifact from the Finnish Civil War.

One of the oldest structures in Helsinki is this burrow grave that dates back to the Bronze Age.