The geographical center of Budapest is marked with a 10-foot-tall stylized zero.

This statue of a falling man commemorates a teenage martyr of the Hungarian Revolution.

Late at night, the bust of the "Dracula" actor was snuck onto the facade of this Budapest castle.

This hidden art nouveau gem was designed by an architect in search of a national style.

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

Museum dedicated to the terror regimes of Hungary.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

Once the home of a hermetic monk, this cave now houses a small church.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

The largest of London's subterranean rivers and once a mad, bad center of London life.

Famously misunderstood wonder of the ancient world

As one of the world's largest hydroelectric dams this plant took two countries to get built.

"Respectful to the dead, safe and sanitary to the living, dedicated to the Genius of Memory..."

The most loyal of little dogs, or a Victorian era publicity stunt?

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona’s iconic (but controversial) church was finally completed in 2026—a century after the death of its architect.

This bustling Italian plaza is built on the ruins of an ancient Roman amphitheater.

Fortified medieval tower house with lovely roof garden.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

A series of waterfalls so massive they straddle the border of Argentina and Brazil.