A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the 20th century.

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

Eat the ultimate iteration of Portugal's most beloved pastry.

A hidden highland of peaks and pastures, largely unchanged since medieval times.

Two buildings named after their windows that make it look like a sea of television sets plastered to a wall.

This 15th-century Serbian Orthodox monastery also contained a school for illuminating manuscripts.

For over 40 years, this quaint little house has teetered on a rock in the middle of a river.

A pair of connected skyscrapers form this symbolic gateway.

Nikola Tesla's ashes are held in a golden sphere, surrounded by his works.

Structure built from the skulls of vanquished foes.

These abundant, over-the-top monuments are so widely scattered that they define the entire compact capital cityscape, often leading to jokes about whether there are more statues than residents.

This fortress dates back to the 6th century and is also the site of a controversial abandoned restoration project.

More than 5,000 years old, D27 is the largest dolmen in the Netherlands and was already standing long before Stonehenge and the Egyptian pyramids were built.

Oldest World War 2-themed museum in Western Europe.

These giant yellow bowling pins seem to be defying gravity.

At the base of this tower, a plaque marks the original center point of the Netherlands.

Located inside Hoge Veluwe National Park, this museum began as the private collection of a prominent female art collector.

This large open-air museum showcases the ordinary lives of the people of the Netherlands and pre-industrial crafts and practices.

The tallest mountain in mainland Netherlands isn't actually very tall.

Building Men of War and Indiamen from Holland's Golden Age.

The struggle of a small Dutch island against the sea.

The location of the world's first telescope demonstration.

The 20-mile causeway that separates the Netherlands from the sea.

The history of sea-faring refuse and disaster is on cramped display in this Netherlands folk museum.